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`
Remove quotes aroung etcd_url value

I get errors like this with etcd_url = 'http://127.0.0.1:4001':
urllib2.URLError: <urlopen error unknown url type: 'http>
minor typo fixes for the rolling update guide
Merge pull request #5385 from tgerla/docsfixes

minor typo fixes for the rolling update guide
Merge pull request #5382 from a-sk/devel

Remove quotes aroung etcd_url value
Update ansible.cfg

Lookup plugins do not warrant settings in ansible.cfg.
Update constants.py

Lookup plugins for optional web services do not warrant advertising in ansible.cfg.
Remove depedency of lookup plugin on setting in ansible.cfg
Swapped conditions of the changed if statements
Missed prefixed variable attribute
Merge pull request #5405 from sivel/guide-rax-fix

Rackspace Guide Example Fix
Use a docsite theme that is in source control, work in progress.
Fixing a typo in the Amazon Web Services and Rackspace Cloud guides
Use the sphinx_rtd_theme
Remove static theme files since we're just grabbing the theme from pip.