error message correction
Cosmetic change: fix comment.
Add an interface method to get a joint transformation.
Add a python class for quaternions.
Fix some compilation warning.
Update to new prototype of hpp::core::LockedDof::create.
Fix documentation.
Enhance python code for corba client

  - add class ProblemSolver that forwards calls to problem.idl client,
  - add methods in Robot class.
Reference python classes in the documentation
Merge remote-tracking branch 'upstream/master'

Conflicts:
	src/problem.impl.cc