Define RSTRING_NOT_MODIFIER so Rubinius optimized String usage.
Added simple transparency test images from PNG test suite.
Fixed ChunkyPNG dependency.
Released oily_png gem version 1.0.1.
New gem management tasks
Added Travis CI config file
Add accessors for R,G,B,A Pixels

This was mostly done as an exercise in writing native extensions. It did
come to light that some existing extensions in the Color module were not
being picked up (compose_quick). I re-jigged some of the includes, but
I'm not terribly sure of how Ruby handles these things.
* Added native extension for Canvas.steps.

This helps with resampling (alteast for nearest neighbour), as most
of the time is spent choosing what pixels to use.

Performance-wise
Original Implementation = 1x
Native (this)           = 4x

* Added tests for resampling.rb
Wrote native extension to do nearest neighbor resampling.

This is substantially faster than the original one. There is room
for gains.

From benchmarking it's about 20-50x faster than the previous code,
and likely much faster on larger images.

** AMEND: Incorperated comments from wvanbergen.
Added some unused_parameter macros to surpress useless warnings
Depend on latest version of chunkypng.
Only include ruby.h - it will include everything else.
Released oily_png gem version 1.0.2.
Silence some more warnings.
Use rubygems instead of outdated rubyforge.
Small code cleanup.
Fix upscaling of lower bitrates to be compatible with ChunkyPNG again.
Update Travis CI config.
Released oily_png gem version 1.0.3.
Bilinear resampling in C