A go at making the depth_packet_stream_parser better.

Iterates through all bytes to find footer.
Copy data in chunks.
Doesn't use additional working buffer.
Adds timestamp
added libfreenect2/config.h defining all platform and build configuration dependend macros; fixes #100, includes #69
updated exports of templated classes to fix visualc++ problems
Opencl uses M_PI, which is defined <math.h> with _USE_MATH_DEFINES defined.
Added another Enviorment variable on windows.

Mine is AMDAPPSDKROOT instead of ATISTREAMSDKROOT.

And cleaned a bit how it was searching.
OpenCV_INCLUDE_DIR to OpenCV_INCLUDE_DIRS
Added FindLibUsb and FindTurboJPEG cmake files, to search for the respective libraries, instead of hardcoding in a sub depend folder.

Added FindGlew as the one shipped with cmake only works on linux and has no GLEW_ROOT_DIR to set in enviroment variables.

Only testet on windows.

Conflicts:
	examples/protonect/CMakeLists.txt
Merge remote-tracking branch 'christiankerl/generate_macro_header' into develop
Merge branch 'depthpacketparse' into develop

Conflicts:
	examples/protonect/include/libfreenect2/frame_listener.hpp
Added LIBFREENECT2 to the use of LIBFREENECT2_WITH_OPENCL_SUPPORT in packet_pipeline.