The mls_results_ vector did not need to be allocated for most of the
Moving Least Squares methods. However, a reference to an entry in this
vector was needed for calls to computeMLSPointNormal, which is why it
was being allocated in full. This commit causes the vector to be resized
to 1 for those methods that don't need the full version, and then a
reference to entry 0 is passed. The decision was made not to modify
computeMLSPointNormal because it needs to be thread-safe and I do not
have the means to test the OpenMP version of the code. Identical
modifications were made to MovingLeastSquaresOMP::performProcessing as
to MovingLeastSquares::performProcessing.

Tests which do not depend on OpenMP still pass.
Relax requirements of manual_registration and pcd_video_player apps

Both apps are currently under `if (OPENNI_FOUND AND BUILD_OPENNI)`
branch, though they do not actually require openni. This commit moves
them outside of this condition.
Including GRSD a global radius-based surface descriptor

GRSD is developed by Zoltan-Marton, this was a old patch as part of his branch being included into the trunk
Adding test files for RSD and GRSD.

style guide issues resolved
Error when compiling for VTK 6
Merge pull request #817 from fran6co/patch-8

Error when compiling for VTK 6
Merge pull request #790 from desinghkar/grsd_request

Including GRSD a global radius-based surface descriptor
fixed a bug of the Ptr typdef in search::KdTree
Merge pull request #820 from prclibo/master

fixed a bug of the Ptr typdef in search::KdTree
Move default argument values from definition to declaration
Merge pull request #821 from taketwo/fix-grsd

Move default argument values from definition to declaration
Fix a typo in test_rsd_estimation.cpp
Merge pull request #822 from taketwo/fix-grsd

Fix a typo in test_rsd_estimation.cpp
Merge pull request #785 from mohawkjohn/eliminate_mls_result_resize

Reduced space usage for Moving Least Squares
Merge pull request #798 from taketwo/fix-apps-cmakelists

Relax requirements for manual_registration and pcd_video_player apps