Fixes a bug where a gray-scale color could not be used as concentric color.
Fixes the name of the addAngleValue:andColor: method.

Was: addAngleValue:andClolor:
Now: addAngleValue:andColor:
Fixes the name of the insertAngleValue:andColor:atIndex: method.

Was: insertAngleValue:andClolor:atIndex:
Now: insertAngleValue:andColor:atIndex:
Fixes a typo in the function argument endAngle of createArc().

Was: endAndle
Now: endAngle
Merge pull request #1 from ge-org/some-fixes

Fixes a regression of concentricColor and some typos.