roscpp: fix issues with the packet reordering in the UDP transport

When an out-of-order packet arrived, only the requested read size of the
packet was saved in the reordering buffer. The rest was discarded, which
led to protocol synchronization problems.

Also, out-of-order blocks should be discarded in one piece.
fix restoring thread context when callback throws an exception (fix #219)
avoid calling PollManager::shutdown() repeatedly (fix #217)
add boolean attribute 'subst_value' to rosparam tag in launch files (fix #218)
add missing exception in rosnode_ping() api doc
add some more warning for obviously wrong ROS_HOSTNAME and ROS_IP (fix #134)
add roslaunch-complete that provides arg-completion
roslaunch: prvide completion for args using 49489d4cbbb999798e7072cdc8c6d987c617ce3e
This overrides the default rosbash completion.
roslaunch: add completion for --skip-log-check and --ros-args options
allow passing arguments to add_rostest() (fix #232)
modified roslaunch (find PKG) to consider path behind it for resolve strategy
Merge pull request #233 from ros/roslaunch-find-only

modified roslaunch (find PKG) to consider path behind it for resolve strategy
fix missing generation of constant definitions for services (ros/gencpp#2)
fix regression of 9ef16d5944dbe6b27b2cec015eb8acac3600b3e7 for fallback behavior of roslaunch find, remove obsolete code
fix roslaunch find to only consider files as executable (regression of 9ef16d5944dbe6b27b2cec015eb8acac3600b3e7)
add manual test script for keeping protocol sync on dropped udp packets in roscpp (#226)
Merge pull request #226 from x-quadraht/groovy-devel

roscpp: fix issues with the packet reordering in the UDP transport
Fix print function calls in rosbag_main.py

- The print call in ProgressMeter prints 'None' and a newline to the
  screen on every update which looks terrible in tools like 'rosbag
  compress'.  Change to not output a newline and still flush the output.
- Several calls to 'print', but it's now a function so it needs to be
  evaluated to print a newline.
Fix missing newlines in rosbag error messages

In rosbag_main.py, switch all calls to sys.stderr.write(args) to
print(args, file=sys.stderr).  This makes the error messages more
readable.
Merge pull request #237 from bcharrow/groovy-devel

Fix printing in rosbag