Update exrmultipart.cpp

Usage of isdigit without including cctype results in build fail in windows(VC++ 2012)
Adding AVX path for the inverse DCT used by DWAA|B_COMPRESSION, and
some minor reformatting to match coding conventions
Updating macro arg format to be consistant
Added "#include <algorithm>" to Imath/ImathMatrixAlgo.cpp and testJacobiEigenSolver.cpp to fix for vs2013
Added lots of fixes for missing exports. Builds cleanly for both debug and release on win7 using visual studio 2013 express (tested x64 only)
Also added a "define NOMINMAX" to ImfDwaCompressor.cpp
Added suggested changes (mostly annotating the windows specific fix in ImfDwaCompressor.cpp as well as exporting classes instead of their members)
added ifdef to windows specific #define NOMINMAX in ImfDwaCompressor.cpp
Adding build system check for inline asm with AVX instructions. This
should hopefully catch cases where the toolchain doesn't support
inline asm + AVX
Merge branch 'sriravic-master' into develop
Merge branch 'dwa_avx_idct' of https://github.com/karlrasche/openexr into karlrasche-dwa_avx_idct
Merge branch 'karlrasche-dwa_avx_idct' into develop
Merge branch 'avx_inline_asm_check' of https://github.com/karlrasche/openexr into karlrasche-avx_inline_asm_check
Merge branch 'karlrasche-avx_inline_asm_check' into develop
Merge branch 'develop-vs2013express' of https://github.com/instinct-vfx/openexr into instinct-vfx-develop-vs2013express
Merge branch 'instinct-vfx-develop-vs2013express' into develop