Fixes for Windows:

* Augment the stock FindJPEG cmake module to also find the newest
  versions for each library.

* FindOpenEXR.cmake and FindIlmBase.cmake modules now also find OpenEXR
  2.1 libs build cmake. On Windows these libraries have an _2_1.lib
  version suffix by default.

* Remove the add_dll_files step for windows installation. The dlls
  listed in the macro are all hardcoded and outdated paths depending on
  certain library versions used and break the make install command.
Adjust reference output for some platforms
maketx: --attrib, --sattrib, --sansattrib (works like oiiotool)