OS X Yosemite support

OS X doesn't follow server & return 10.10 for Yosemite 10.10.0.
Here is a simple workaround that closes #25
Merge pull request #27 from MoOx/patch-1

OS X Yosemite support
Merge pull request #23 from hmeine/master

enable --remove of multiple dock items at once
Bump version to 2.0.1
Update README for 2.0.1
restore Maverics support