Updates to Windows Azure inventory from Tower.  

changed check to avoid OS X broken sem_getvalue()

fixes #11988

fixes #11907

refactored the options a bit, new inventory_opts made sense to always group
fixes #7917

fixes #11979

Add become support for OpenBSD doas

fixes #11982

* Speed up serialization of hostvars by simply using the internal
  dictionary used for cached lookups
* Use blocking gets/puts on queues instead of spin locking
* Merge sequential implicitly created blocks

cloudstack: add more common returns

Fix variable name mis-match in website docs for ANSIBLE_LIBRARY. 

now passes the test of skipping list when dict attribute is undefined, added deprecation warning as this seems like bad behaviour

made sure they all look in files/vars/template dirs also when executed in play and not only from task

Update intro_installation.rst

Change 'SSH' to upper case.

Improve documentation.

 * now it uses -n to get immediate error if no password is supplied and one is needed,
   this should fix the issue with sudo hanging waiting for input.
 * made -k configurable, this can break changing become_users in play if left out,
   but opens up the possiblity of OTP support.