Python wrapper: prevent *Ptr classes from being created from Python

This avoids segfaults due to improper use of *Ptr objects like CtxPtr.

Signed-off-by: Robert Xiao <brx@cs.cmu.edu>
Python wrapper: handle non-standard modes properly

Signed-off-by: Robert Xiao <brx@cs.cmu.edu>
Ignore .pyc files from Python

Signed-off-by: Robert Xiao <brx@cs.cmu.edu>
python: Add .gitattributes which treats the Python freenect.c as binary

Signed-off-by: Robert Xiao <brx@cs.cmu.edu>
Update python wrapper.

Signed-off-by: Robert Xiao <brx@cs.cmu.edu>