Test compile fixes.

 - For Ubuntu 13.04 - gcc 4.7.3
 - For Linux Mint 16
Fixing testCore output re-direct.

OS specific problem (Ubuntu). This works on CentOS, but is a slight change from the original commit provided by Ben.

See here for details:
http://blog.stefan-weigand.de/2008/09/23/syntax-error-bad-fd-number/index.html

Fixes #51
Removed the inverse function form ColorTransform.h and SpaceTransform.h.

The inverse function was causing Cortex to not build on Linux Mint 16.
Fixes to get IECoreNuke to compile.

Fixes #258
Merge pull request #260 from andrewkaufman/propersquid-feature/UpdatingForMint

Updating for Mint and Ubuntu