Log Message:
Update to 1.1.7

Changelog:
Release 1.1.7 (21 Feb 2013)
---------------------------
* Back out dangerous change to thread.h that was in 1.1.6, which could
  cause performance problems.
* Compile fix for WIN32 in strutil.cpp
* Compile fix for Windows XP - add implementation of InterlockedExchangeAdd64

Release 1.1.6 (11 Feb 2013)
---------------------------
* Fix bug that could generate NaNs or other bad values near the poles of
  very blurry environment lookups specifically from OpenEXR latlong env maps.
* Fix bug in oiiotool --crop where it could mis-parse the geometric parameter.
* Fix bug in ImageCache::invalidate() where it did not properly delete the
  fingerprint of an invalidated file.
* Cleanup and fixes in the oiiotool command line help messages.
* New function ImageBufAlgo::paste() copies a region from one IB to another.
* oiiotool --fit resizes an image to fit into a given resolution (keeping the
  original aspect ratio and padding with black if needed).
* ImageBufAlgo::channels() and "oiiotool --ch" have been extended to allow
  new channels (specified to be filled with numeric constants) to also be
  named.
* New function ImageBufAlgo::mul() and "oiiotool --cmul" let you multiply
  an image by a scalar constant (or per-channel constant).
* Important maketx bug fix: when creating latlong environment maps as
  OpenEXR files, it was adding energy near the poles, making low-res
  MIP levels too bright near the poles.
* Fix to "oiiotool --text" and "oiiotool --fill" -- both were
  incorrectly making the base image black rather than drawing overtop of
  the previous image.
* Fix FreeBSD compile when not using TBB.
* New oiiotool --swap exchanges the top two items on the image stack.