The ipavault module was returning a single string value when retrieving
data. To keep consistency with other modules, it should return a dict
with the `data` variable in it.
This change modifies the result of ipavault to be a dict and also fixes
relevant tests, examples and documentation.
Allows changing passwords of symmetric waults, using a new variable
`new_password` (or the file-base version, `new_password_file`). The
old password must be passed using the `password` or `password_file`
variables that also received new aliases `old_password` and
`old_password_file`, respectively.
Tests were modyfied to reflect the changes.
This change split vault tests in several files, organized by vault
type and operation (vault vs. member) so that it is easier to add
new tests for issues and verify if tests are missing.
