Add ability to use rsync rather than cp on remote

This enables finer control (via excludes) when seeding the destination
directory for rsync. Because we know we have rsync available, we can use
rsync rather than cp by using configuration like this example:

	  strategy: rsync
	  rsync:
		copy: true
		copy_tool_rsync: true
		rsync_excludes: ["assets", "silverstripe-cache"]

The default tool remains cp, so this change is backward-compatible.
Fixed namespace for Filesystem tasks
Removed unused use statements
Merge pull request #66 from iambrosi/use_statements

Removed some unused use statements
Merge pull request #65 from iambrosi/namespace_fix

Fixed namespace for Filesystem tasks
fixed failing testing for successful json_decode
Merge pull request #68 from JanMalte/patch-1

fixed failing testing for successful json_decode
fixes #73 missing "Task" suffix for LinkSharedFiles
Merge pull request #74 from JanMalte/patch-2

fixes #73 missing "Task" suffix for LinkSharedFiles
Tweaks and fixes.
Merge branch 'master' of https://github.com/andres-montanez/Magallanes

Conflicts:
	Mage/Task/Factory.php
Tweak SPYC.
Code refactoring.
Commented code should not be commited #inslight
Reorganize common Deployment code.
Tweaks on FileSystem Tasks.
Merge pull request #63 from oddnoc/remote-rsync

Add ability to use rsync rather than cp on remote
Review and rework Composer tasks.
Add Rollback command as alias.
Issue #70, makes --release mandatory.