rtt_rosparam: Make it better

[jbohren]

• [x] add better support for vectors
• [x] add better support for different namespace resolution (relative/absolute/private/component)
• [x] add service requester
• [ ] create unit tests

[jbohren]

@meyerj Here's a new from-scratch implementation (which should allow addition of other commonly-used container types later)

https://github.com/jhu-lcsr-forks/rtt_ros_integration/blob/new-rtt-rosparam/rtt_rosparam/src/rtt_rosparam_service.cpp

[jbohren]

Getting this working also had this side-effect: https://github.com/ros/ros_comm/pull/279

[jbohren]

And here's a service requester: https://github.com/jhu-lcsr-forks/rtt_ros_integration/blob/new-rtt-rosparam/rtt_rosparam/include/rtt_rosparam/rosparam.h

[jbohren]

Closing this in favor of specific unit test ticket