Added 'given_command' to local() 'out'

This makes adds the 'command' attribute to local()'s return, as
in run() and sudo() to make the initial command accessible after
execution.
replace non-existing log_action() with print()

Inspired by: [Python Fabric NameError: global name 'log_action' is not defined](http://stackoverflow.com/q/22696486/4279)
Fixed the url of the contributing guide
Rephrase nohup part of FAQ
Fix bug in env.use_shell docs - run/sudo functions doesn't have use_shell argument.
Merge branch 'master' into 1106-int
Changelog, closes #1106
Merge pull request #1110 from konradhalas/master

Fix bug in env.use_shell docs
Merge pull request #1109 from humanfromearth/master

Fixed the url of the contributing guide
Clean up references to contribution-guide.org & add explicit note about changelog location
Set the reboot command

This update makes it possible to set the reboot command. In our case when we use molly-guard to prevent accidental reboots we need to use /sbin/reboot and not reboot.
Cleanup of #1101. Added changelog entry
Merge branch 'master' into local-function-given-command
Simplify some main tests.
Add an env var effective_roles specifying roles used in the currently executing command.
Add command and real_command attributes to local return value.
Update docs - env.all_hosts default value

Default value for env.all_hosts is [], not None.
Merge branch 'master' into 1112-int

Conflicts:
	sites/www/changelog.rst
Merge pull request #1114 from pbetkier/docs-env-all_hosts-default-value

Update docs - env.all_hosts default value
Merge branch 'master' into 1113-int

Conflicts:
	sites/www/changelog.rst