Simulator cleanup

[rethink-imcmahon]

This PR contains several commits aimed at improving the user experience and cleaning up baxter_simulator

• Added CMakeLists install target directories that were missing (required for Debian installs)
• Removed a console warning about unknown property der
• Added signal handlers for baxter_sim_io to properly catch ctrl+c and exit cleanly
• Deleted an allocated UI object in baxter_sim_io
• Set the controller_manager to exit as soon as ctrl+c is hit (we destroy the controllers already by the ros_control controller nodes dying) (#54)
• Added some xml tags to launchfiles for prettiness
• Added run_depend's for baxter_simulator to make it a proper metapackage
• Removed unused shoulder signal which printed messages to the console (#57)

[rethink-imcmahon]

Commit 9ea436b resolves Issue https://github.com/RethinkRobotics/baxter_simulator/issues/54

[rethink-imcmahon]

@rethink-rlinsalata could you please glance over these commits? They're all relatively small, but quite beneficial