Include test_stdint.h to get stdint types for MSVC
Use the common stdint typedefs in processing as well

This fixes building test/processing/ProcessUT_AdaptiveQuantization.cpp
with MSVC.
Merge pull request #1238 from mstorsjo/fix-msvc-tests

Fix building the tests with MSVC
Merge remote-tracking branch 'upstream/master' into travis.osx