"Working" Qt 5 port.

Still needs work on includes, .pro file resources, new OSX memory leaks.
Factor downsampler out into library v0.2

Lose Secret Rabbit Code dependency
Copyright bump
Compatibility with LFK 0.2.1

And removal of the backward compatible preference-loading code.
Update to match Exception class in LKF
Key writing to FLAC files

Awaiting feedback on de facto standard for frame name
Small exception handling fix
Tagging refactor
Curve shaping to colour schemes
Minor cleanup
ID3 v2.3 preservation, improved tag writing feedback
Changes to keep pace with LKF
Hack for poorly encoded MP3 duration estimates