Merge pull request #188 from gillham/master

Repair Mac builds & add 2MHz & 4MHz sample rates for Arduino Generic Logic Analyzer v0.11.
Fixed/simplified OSX app bundle creation.
Bumped to RC2.
Fixed position where annotations were painted.
Preparing for 0.9.7 release.
Updated site to reflect new 0.9.7 release.
Bumped version to snapshot.
Issue #190: allow CS to be inverted;

- some SPI implementations use a normally-low CS signal, instead
  of a normally-high CS signal. The current decoder tool couldn't
  cope with such signals. Added an additional option that allows
  you to "invert" the CS signal.
Issue #190: add new setting to user prefs.