Consolidate launch files

[emcauliffe]

Make it easier to bring up the rover

• rosserial into a launch file
• combine joy, cmd_vel_repeater, xbox_drive control into one file (to be run on remote system)
• bringup (parameters to not bring up)
• Navigation
• arm (at some point)
• science
• mapviz, rviz, etc. (base station telemetry)
• panorama

Add notes on how to bring up and operate specific nodes

[emcauliffe]

#44 brings in the cmd_vel_repeater

[emcauliffe]

#60 adds a rosserial launch file