* Simplified some of the Filter code and corrected comments.
* Reordered the filters so that they are displayed from most soft to most sharp.
* Added the Lanczos filter.
* Fixed a bug with the Sinc filter.
* Brought the Reformat node inline with these changes.
Added a sub-pixel sampling mode to the sampler.
Updated the bindings.
Fixed a typo.
Fixed the todo in GafferImage::Sampler. Sampler() now uses GafferImage::ImagePlug::tileOrigin().
Fixed a typo in the Sampler bindings.
* Fixed bugs with the filters and the sampler.
* Out of bounds samples now return 0.
* Added test cases for the above.
* Added the boundingMode parameter to GafferImage::Sampler() that defines what is returned when a sample that is out of bounds is made.
  - Current options are: Black, Clamp.
* Changed the Reformat node to use the "Clamp" method to maintain the current look.
* The above changes fix the "streaking" issues when using the ImageTransform.
* Added test cases for sampling with the different bounding modes.
* Added bindings for the different bounding modes.
* Updated the test cases for the Reformat node to include the Lanczos filter and the new fixes to the Sinc and Mitchell filters.
* Renamed the test images to match their resolutions.
Added GafferImage::Sampler::Hash() and test cases for it.
Changed the Style of an Enum declaration.
Removed a completed \todo
Fixed @param tags.
Added python bindings for GafferImage::Filter.
Removed the requirement of a Filter from the Sampler() constructor.
Added test cases for the GafferImage.Filter classes.
Rebasing.
Corrected a bug in Filter.h where the wrong base class had been defined in the decleration of the CatmullRom filter.
Merge pull request #290 from goddardl/SamplerUpdates

Sampler and Filter Updates