Fix spawner choke when namespace is unspecified.

Add missing check in conditional.
Merge branch 'master' of https://github.com/willowgarage/ros_control
Build script fixes.

- Add missing tinyxml dependency.
- Drop unnecessary Boost dependency.
- Add URDF parsing code to rosbuild.
Code consistency fixes.

- Add missing header guard.
- Make existing header guards comply with the NAMESPACE_CLASS_H convention.
- Make Doxygen structural commands start with '\' instead of '@', as most of the
  new ros_control code.
- Remove trailing whitespaces.
- Remove commented-out code used for debugging.
Minor Doxygen fixes.

- Revert back to using \file instead of \brief, as the latter was documenting
  the namespace and not the file scope.

- Escape angular brackets on XML tag documentation, as Doxygen was parsing them
  printing warnings.

@davetcoleman
Merge pull request #88 from ros-controls/master

Merge master into hydro-devel for release to bloom
Merge branch 'hydro-devel' of github.com:ros-controls/ros_control into hydro-devel
Made joint_limits_interface match hydro version number
Created changelog for ros_control metapackage, but not the other packages
0.5.0