Add rotated rectangle draw and fill methods

[BillMerryman]

These methods implement the ability to draw and fill rectangles rotated by a given angle in degrees.

[BillMerryman]

@ladyada for review.

[ladyada]

thanks! please also add some example to test this code, maybe displaying rotating rectangles - so we can easily verify functionality on platforms/displays :)

[BillMerryman]

Wasn't sure where you wanted an example, so I placed one in the 'examples' directory in a directory called 'RotatedRectangleTest'. Commented the display-specific code.

[BillMerryman]

@ladyada for review.