Remove outdated note about apt module

Undocument override hosts (gone in 0.4, use -i "host1,host2" if you must, but want to leave that undocumented
as it's not a best practice so much.

Clarifications/fixes for executable inventory examples

Conflicts:
	rst/modules.rst

Change the 'name' value for Playbook's variable example

Previously, there were two entries for 'dest'. I've combined them in a
way that makes sense to me.

This will be superfluous when 'path' is made. Ideally, I'd like to see
'path' have the bulk of the definition, and 'dest' to be an alias to
'path'.

This reverts commit 21550f65.

'make a directory' is a bad description, since the command "template …"
doesn't actually create a directory.

Update file documentation for se* options

Add UID to user module documentation

Describes how you can use '_default' to seuser, serole, setype, and
selevel to use the default context from the policy, if available.