New sysaccount management module

There is a new sysaccount management module placed in the plugins folder:

    plugins/modules/ipasysaccount.py

The sysaccount module allows to ensure presence or absence of system
accounts.

Here is the documentation for the module:

    README-sysaccount.md

New sysaccount example playbooks:

    playbooks/sysaccount/sysaccount-absent.yml
    playbooks/sysaccount/sysaccount-disabled.yml
    playbooks/sysaccount/sysaccount-enabled.yml
    playbooks/sysaccount/sysaccount-present.yml
    playbooks/sysaccount/sysaccount-privileged.yml
    playbooks/sysaccount/sysaccount-unprivileged.yml

New tests for the module:

    tests/sysaccount/test_sysaccount.yml
    tests/sysaccount/test_sysaccount_client_context.yml

README-sysaccount.md

@@ -0,0 +1,196 @@
+Sysaccount module
+============
+
+Description
+-----------
+
+The sysaccount module allows to ensure presence and absence of system accounts.
+
+Features
+--------
+
+* Sysaccount management
+
+
+Supported FreeIPA Versions
+--------------------------
+
+FreeIPA versions 4.4.0 and up are supported by the ipasysaccount module.
+
+
+Requirements
+------------
+
+**Controller**
+* Ansible version: 2.15+
+
+**Node**
+* Supported FreeIPA version (see above)
+
+
+Usage
+=====
+
+Example inventory file
+
+```ini
+[ipaserver]
+ipaserver.test.local
+```
+
+
+Example playbook to make sure sysaccount "my-app" is present with random password:
+
+```yaml
+---
+- name: Playbook to manage IPA sysaccount.
+  hosts: ipaserver
+  become: false
+
+  tasks:
+  - name: Ensure sysaccount "my-app" is present with random password
+    ipasysaccount:
+      ipaadmin_password: SomeADMINpassword
+      name: my-app
+      random: true
+    register: result
+
+  - name: Print generated random password
+    debug:
+      var: result.sysaccount.randompassword
+
+```
+
+
+Example playbook to make sure sysaccount "my-app" is present with given password:
+
+```yaml
+---
+- name: Playbook to manage IPA sysaccount.
+  hosts: ipaserver
+  become: false
+
+  tasks:
+  - name: Ensure sysaccount "my-app" is present with given password
+    ipasysaccount:
+      ipaadmin_password: SomeADMINpassword
+      name: my-app
+      password: SomeAPPpassword
+```
+
+
+Example playbook to make sure sysaccount "my-app" is absent:
+
+```yaml
+---
+- name: Playbook to manage IPA sysaccount.
+  hosts: ipaserver
+  become: false
+
+  tasks:
+  - name: Ensure sysaccount "my-app" is absent
+    ipasysaccount:
+      ipaadmin_password: SomeADMINpassword
+      name: my-app
+      state: absent
+```
+
+Example playbook to ensure existing sysaccount my-app is privileged
+
+```yaml
+---
+- name: Playbook to manage IPA sysaccount.
+  hosts: ipaserver
+  become: false
+
+  tasks:
+  - name: Ensure existing sysaccount my-app is privileged
+    ipasysaccount:
+      ipaadmin_password: SomeADMINpassword
+      name: my-app
+      privileged: true
+```
+
+Example playbook to ensure existing sysaccount my-app is not privileged
+
+```yaml
+---
+- name: Playbook to manage IPA sysaccount.
+  hosts: ipaserver
+  become: false
+
+  tasks:
+  - name: Ensure existing sysaccount my-app is not privileged
+    ipasysaccount:
+      ipaadmin_password: SomeADMINpassword
+      name: my-app
+      privileged: false
+```
+
+Example playbook to ensure existing sysaccount my-app is disabled
+
+```yaml
+---
+- name: Playbook to manage IPA sysaccount.
+  hosts: ipaserver
+  become: false
+
+  tasks:
+  - name: Ensure existing sysaccount my-app is disabled
+    ipasysaccount:
+      ipaadmin_password: SomeADMINpassword
+      name: my-app
+      state: disabled
+```
+
+Example playbook to ensure existing sysaccount my-app is enabled
+
+```yaml
+---
+- name: Playbook to manage IPA sysaccount.
+  hosts: ipaserver
+  become: false
+
+  tasks:
+  - name: Ensure existing sysaccount my-app is enabled
+    ipasysaccount:
+      ipaadmin_password: SomeADMINpassword
+      name: my-app
+      state: enabled
+```
+
+
+Variables
+---------
+
+Variable | Description | Required
+-------- | ----------- | --------
+`ipaadmin_principal` | The admin principal is a string and defaults to `admin` | no
+`ipaadmin_password` | The admin password is a string and is required if there is no admin ticket available on the node | no
+`ipaapi_context` | The context in which the module will execute. Executing in a server context is preferred. If not provided context will be determined by the execution environment. Valid values are `server` and `client`. | no
+`ipaapi_ldap_cache` | Use LDAP cache for IPA connection. The bool setting defaults to true. (bool) | no
+`name` \| `login` | The list of sysaccount name strings - internally uid. (list of strings) | yes
+`description` | A description for the sysaccount. (string) | no
+`privileged` | Allow password updates without reset. This flag is not replicated. It is needed to set privileged on all servers, where it is needed. (bool) | no
+`random` | Generate a random user password. (bool) | no
+`password` \| `userpassword` | Set the password. (string) | no
+`update_password` | Set password for a sysaccount in present state only on creation or always. It can be one of `always` or `on_create` and defaults to `always`. | no
+`state` | The state to ensure. It can be one of `present`, `absent`, 'enabled', 'disabled',  default: `present`. | no
+
+
+Return Values
+=============
+
+There are only return values if a random passwords has been generated.
+
+Variable | Description | Returned When
+-------- | ----------- | -------------
+`sysaccount` | Sysaccount dict (dict) <br>Options: | Always
+&nbsp; | `randompassword` - The generated random password | If random is yes and sysaccount did not exist or update_password is yes
+
+
+
+Authors
+=======
+
+Thomas Woerner