Add 10-12-14bit (integer) TIFF decoding support
* Add 12bit (integer) TIFF decoding support
An (slow) unpacking step is inserted when the native bpp is not equal to the dst_bpp
Currently, I do not know if there can be several packing flavours in TIFF data.
* added tests
* move sample files to opencv_extra
* added 10b and 14b unpacking
* fix compilation for non MSVC compilers by using more standard typedefs
* yet another typdef usage change to fix buildbot Mac compilation
* fixed unpacking of partial packets
* fixed warnings returned by buildbot
* modifications as suggested by reviewer