Reworking v2 play iterator and fixing some other bugs

Still not working quite right:
* dynamic includes are not adding the included tasks yet
* running roles with tags not quite working right

v2/samples/test_include.yml

@@ -0,0 +1,26 @@
+- hosts: localhost
+  gather_facts: no
+  tasks:
+  - block:
+    - include: include.yml
+      when: 1 == 2
+    - include: include.yml a=1
+      when: 1 == 1
+      notify: foo
+    - include: include.yml a={{item}}
+      with_items:
+      - foo
+      - bar
+      - bam
+    - fail:
+
+    #rescue:
+    #- include: include.yml a=rescue
+
+    always:
+    - include: include.yml a=always
+
+  handlers:
+  - name: foo
+    include: include.yml a="this is a handler"
+