synchronize: allow ansible_ssh_host to be templated

This is already enabled in the runner also.
Allow multiple users to use ec2 inventory scripts

Move the ec2 cache files from a shared /tmp location to the
user's ansible tmp directory.
Fixed false positive on initctl as enable_cmd

Also on update-rc.d
In service module
Fail EC2 inventory better with restricted EC2 users

If a user has full EC2 access but no RDS access, the user
should still be able to query the EC2 inventory, although
will not obtain any information about any RDS instances.
Added prev_state for directory
Move more responsibility to common EC2 module

Moved `AWS_REGIONS` into `ec2` module
Created `ec2_connect` method in `ec2` module
Updated modules able to use `ec2_connect` and `AWS_REGIONS`
Swapped conditions of the changed if statements
Missing "is" in file module description
added more usefull example for jinja2 overrides (this one is actually
used)

Signed-off-by: Brian Coca <briancoca+dev@gmail.com>
added descriptions for yum options

Updated main description to state that the yum module will handle package groups.  Added descriptions for each example, as it is unclear to (some) users that @Name implies a group install.
Merge pull request #5425 from mmoya/docfix

Missing "is" in file module description
Merge pull request #5427 from bcoca/template_docs2

added more usefull example for jinja2 overrides
Merge branch 'devel' of git://github.com/beefsalad/ansible into devel
Use task names in examples.
make examples/DOCUMENTATION.yml a link
include short_description in the module page's title
fix short/full description for elasticache
Add contents to various pages with more than one topic per page.
Fix some small docsite formatting things.
Fix a intra-doc link.