Bump version after tag/release
GIF input plug: Fix build with giflib>=5.1

From giflib-5.1.0's NEWS:
"A small change to the API: DGifClose() and EGifClose() now take a
pointer-to-int second argument (like the corresponding openers)
where a diagnostic code will be deposited when they return
GIF_ERROR."
JPEG support for reporting and controlling chroma-subsampling value
Minor docs fixes
OpenEXR fix writing of subimage name.
(Got attribute name translation backwards.)
oiiotool -help should say if there is no OCIO support.
Python read_scanlines did not honor channel subset, leading to chaos.
Fix raw bug -- open-with-config had the wrong function signature,
was missing a 'const' and therefore not properly overriding the base class.
Fixes #995.
Bump version; oops, should have done that right after last release
Fix segfault in python ImageInput.read_* functions

which happens when calling one of the ImageInput.read_* functions
without specifying a type/format.

The reason:
When not specified, the format would be TypeDesc::UNKNOWN. So, calling
format.size() to determine how much memory to allocate will (probably)
not work.

The subsequent call to the C++ read_* function will further return the
image data in the native format, which will not work together with
C_array_to_Python_array(), which assumes float if format is
TypeDesc::UNKNOWN.

This commit sets format to spec.format (i. e. the native format) if
format is TypeDesc::UNKNOWN to match the behavior of the C++ functions
(i. e. return data in native format).
Fix typo in make_texture docs and header
Newer boost versions
CHANGES and rebuild PDF for release
Post-release bump of versions
Fix gcc 4.9 warning about unused local typedefs
Tighten up error propagation through IC, IB, and oiiotool.

Now we get nice helpful error messages if any of the input images are
corrupt or incomplete.
More tightening up of error reporting for oiiotool.

Found all places that haphazardly wrote error messages or warnings to
cerr or cout, and replaced them with legit error() or warning() calls
so that they all behave the same way including proper exit of oiiotool
with the right return code.
Update testsuite ref output
Fixed typo

Just found this typo when reading though.
Move grid.tx and checker.tx from oiio-images to testsuite/common/textures.

This is really being done because the grid.tx in oiio-images is really
old and I want to re-txmake it for better filtering, higher quality
resize, and more modern metadata. OK, but if I do that, it'll make old
branch testsuites fail horribly. So the solution is to move the texture
to the oiio tree itself. This is an icky one-time thing. Sorry.