UAVTalk: rewrite serial driver

Using snippets from:
http://gitorious.org/serial-port/serial-port/blobs/master/3_async/AsyncSerial.cpp

Move all serial IO to io_service thread.
UAVTalk: redo io_service thread
Add dirty test for uavtalk
ROS_x -> ROS_x_NAMED
Build: add USE_UAVOBJGEN option for overwrite uavobjgenerator location
UAVTalk: disable uavtalk.c debugging