chessboard masking in projector calibration using rotated rectangles.

Dear Nicolas,

Commit 3d0a90f fixes a change of function names introduced by nestk commit df57445a, which caused a compilation error.

Commit 4916b4c improves the projector calibration by masking chessboards with rotated rectangles.
The old axis-aligned rectangles did not work if the kinect views the scene from a different angle and the size of the printed board is smaller.