Added ability to start and stop existing EC2 instances.
Added ability to create EC2 volume from snapshot

ec2_vol module now takes optional snapshot argument
Added relevant module argument handler and documentation
Simplified p.poll handling
Allow su_user to be templated, same as sudo_user.
Fixing bug relating to su without an su_pass
Merge branch 'feat/ec2_start_stop' of git://github.com/Geryon/ansible into Geryon-feat/ec2_start_stop
Fix start/stop example in ec2
Add skip_tags to ansible-playbook man page
Merge pull request #5793 from garaden/skip_tags

Add skip_tags to ansible-playbook man page
Merge pull request #4508 from willthames/ec2_vol_snapshot

Added ability to create EC2 volume from snapshot
Add ec2_vol snapshot example from #4189
Fixes #5750 Fail on missing ~/.ssh and ignore accept_hostkey if stricthoskeychecking is off
self.su_user is done earlier in the code path, and is auto-vivified from
su_user_var.  My last PR was only half merged, and when the bug fix for
the su/su_pass typo was merged, the removed line in this commit was
mistakenly reintroduced.
Merge branch 'slow_ssh' of git://github.com/lberruti/ansible into lberruti-slow_ssh
Support keyring for the api_key
Support additional attributes that would allow the rax modules to work with other OpenStack clouds
identity_type is set dynamically above
Support using ~/.pyrax.cfg and multi environments
Only specify to USE_KEYRING as the api_key/password when we actually got a keyring_username from ~/.pyrax.cfg
Make sure to also include the region when using keyring_auth