Removed deprecated boost-filesystem functions and improved for v3.

Compilation failed with -DBOOST_FILESYSTEM_NO_DEPRECATED.
Using boost-filesystem v3 requires explicit calls to path::string() to
preserve compatibility between *nix and Windows.
Fix for boost-filesystem v3 on Windows.

Ideally this should use QString::fromWCharArray (fn.filename().c_str())
on Windows to preserve the internal format of boost::filesystem::path.
However the offical builds of Qt for msvc do not use wchar_t as a built-in
type (it is a built-in type by default) causing a linking error.
This will not be fixed until Qt5.
Fix a warning by using the same type as the forward declaration of ImageRec.
Replaced path::extension() by OIIO's Filesystem::file_extension as per comments on github.
Add Filesystem::filename, and use it in place of a few tricky boost ifdefs.  Also add Filesystem::extension that is like file_extension but includes the dot (and thus is compatible with boost).
fixed link to reference images for j2k plugin
Fix IC/IB not able to report what was in the original file, used to solve a "bug" wherein oiiotool would always output float images instead of the original format.
Straighten out displaywindow vs datawindow semantics.
* Add ImageOutput::supports("displaywindow").
* oiiotool output checks for displaywindow support, if not found will
  pad or crop to make pixels match the "full" (display) size.
* New oiiotool options: --fullsize (set full size), --fullpixels (set full
  window to be pixel window), --crop (adjust pixel window, padding or
  deleting pixels if necessary), --croptofull (set pixel window to be
  full/display window), --noautocrop (turn off auto cropping when outputting
  to formats that don't support displaywindow).
* Other straightening out of oiiotool, ImageBuf, and ImageCache to support
  these features or fix minor bugs found along the way.
oiiotool - encapsulate 'deferred' idiom rather than repeating
Removed Microsoft Visual Studio compilation warnings from the oiio command line tools.
Added autoscanline option to make autotiles as wide as the whole image.
This corresponds better with the loading costs of untiled images and
improves cache performance.
Document ImageCache/TextureSystem 'autoscanline' option
CHANGES and CREDITS updates.
Rebuild PDF docs
Have TS and IC accept attribute "options", that is a comma-separated list
of name=value settings (e.g., "max_memory_MB=256,max_files=1000") that
will be parsed and used to set the individual attributes of those names.
This is helpful if you want an app that can just pass such a string through,
including setting new or experimental IC/TS options, without the app needing
to be modified for each new/experimental OIIO option.  Furthermore, IC/TS
upon startup will check for OPENIMAGEIO_IMAGECACHE_OPTIONS and
OPENIMAGEIO_TEXTURE_OPTIONS environment variables and seed options using
those.
Also expose the helper template optparser, in case other apps want to use it.
Improve robustness of texture lookups for very small filtering footprints
Update ref images after latest texture fix
CHANGES updates
fix cineon compilation on Windows. Visual Studio < 10 don't have stdint.h header
Fixes for FreeBSD: Arbitrary unix platform detection, use uint64_t for imagesize_t, use TBB instead of gcc builtin atomics on non-x86_64 BSD, FreeBSD build fixes for ptex.