OpenImageIO 2.2.14.0

Release 2.2.14 (1 May 2021) -- compared to 2.2.13

• JPEG: Improve reading of files with mildly corrupted headers. #2927
• TIFF: Support IOProxy for input. #2921
• BMP: Improve performance by eliminating wasteful per-scanline allocation
  and needless data copying. #2934
• Build/CI: Fix all the build_*.bash scripts to not use cmake --config flag,
  which was harmlessly ignored but is flagged as an error for CMake 3.20.
  #2931
• Build: More fixes related to supporting a wide range of OpenEXR versions,
  and making our exported cmake configs correctly transmit dependencies on
  OpenEXR include paths. #2935 #2941 #2942 #2947
• ImageBufAlgo::fillholes_pushpull: added logic to correctly set the spec's
  alpha_channel field when generating sub-images. #2939
• Python: MakeTxBumpWithSlopes enum value had been inadvertently omitted
  from the Python bindings. #2951