Log Message:
Changes 1.7.0:
* Added new atttribute types:
  M33dAttribute   3x3 double-precision matrix
  M44dAttribute   4x4 double-precision matrix
  V2d             2D double-precision vector
  V3d             3D double-precision vector
* Bug fix: crash when reading a damaged image file (found
  by Apple).  An exception thrown inside the PIZ Huffman
  decoder bypasses initialization of an array of pointers.
  The uninitialized pointers are later passed to operator
  delete.
* Bug fix: crash when reading a damaged image file (found by
  Apple).  Computing the size of input certain buffers may
  overflow and wrap around to a small number, later causing
  writes beyond the end of the buffer.
* In the "Technical Introduction" document, added
  Premultiplied vs. Un-Premulitiplied Color section:
  states explicitly that pixels with zero alpha and non-zero
  RGB are allowed, points out that preserving such a pixel can
  be a problem in application programs with un-premultiplied
  internal image representations.
* exrenvmap improvements:
  - New command line flags set the type of the input image to
    latitude-longitude map or cube-face map, overriding the
    envmap attribute in the input file header.
  - Cube-face maps can now be assembled from or split into six
    square sub-images.
  - Converting a cube-face map into a new cube-face map with
    the same face size copies the image instead of resampling
    it.  This avoids blurring when a cube-face map is assembled
    from or split into sub-images.
* Updated standard chromaticities in ImfAcesFile.cpp to match
  final ACES (Academy Color Encoding Specification) document.
* Added worldToCamera and worldToNDC matrices to ImfStandardAttributes.h
* Increased the maximum length of attribute and channel names
  from 31 to 255 characters.  For files that do contain names
  longer than 31 characters, a new LONG_NAMES_FLAG in the fil
  version number is set.  This flag causes older versions of
  the IlmImf library (1.6.1 and earlier) to reject files with
  long names.  Without the flag, older library versions would
  mis-interpret files with long names as broken.
* Reading luminance/chroma-encoded files via the RGBA
  interface is faster: buffer padding avoids cache thrashing
  for certain image sizes, redundant calls to saturation()
  have been eliminated.
* Added "hemispherical blur" option to exrenvmap.
* Added experimental version of I/O classes for ACES file
  format (restricted OpenEXR format with special primaries
  and white point); added exr2aces file converter.
* Added new constructors to classes Imf::RgbaInputFile and
  Imf::TiledRgbaInputFile.  The new constructors have a
  layerName parameter, which allows the caller to specify
  which layer of a multi-layer or multi-view image will
  be read.
* A number of member functions in classes Imf::Header,
  Imf::ChannelList and Imf::FrameBuffer have parameters
  of type "const char *".  Added equivalent functions that
  take "const std::string &" parameters.
* Added library support for Weta Digital multi-view images:
  StringVector attribute type, multiView standard attribute
  of type StringVector, utility functions related to grouping
  channels into separate views.