Moved argtypes and restype into each respective function.  #125
openjp2's decode_tile_data handler was returning the codec.  It should not.  #125
Forgot to actually set argtypes for openjp2 read_header function.  #125
Fixed typo.
Merge branch 'issue125' into devel
Merge branch 'devel' of github.com:quintusdias/glymur into devel