OS X Yosemite (10.10) Rosdep entries for vtk and gazebo2

#### Homebrew VTK Update
Recent updates to the homebrew/science/vtk brew have created issues for ROS Indigo install on OSX. 
This can be fixed by removing the __--python__ and __--qt__ options and replacing them with __--with-qt__ on the vtk homebrew dependency.

#### ROS & Gazebo
As noted on the [Which combination of ROS/Gazebo versions to use](http://gazebosim.org/tutorials?tut=ros_wrapper_versions&cat=connect_ros) page, ROS Indigo is only compatible with the Gazebo 2.x branch.