added respawn to install location

nodes with the respawn attribute set to true will silently just not start since respawn is not found by rosrun
Merge pull request #6 from markusachtelik/master

added respawn script to the install location
master_discovery_fkie: fixed class desription
node_manager_fkie: fixed unregistration of nodes
node_manager_fkie: shows error message box on loading a non existent launch file (in favorits)
node_manager_fkie: handling of (node, topics, service) description changed
added missing imports in ssh_handler
Merge pull request #7 from markusachtelik/master

added missing imports in ssh_handler
Merge branch 'master' of http://github.com/fkie/multimaster_fkie
node_manager_fkie: fixed the showing the image of robots