Adding the GraphicsEx extension

GraphicsEx allows for interpolating alpha values and line segment
thickness, while keeping the regular Graphics API clean. Use a
starling.display.graphics.graphicsEx.ShapeEx shape to get access to the
new functions. Very poor documentation, no real samples yet.
Reworked the GraphicsEx API to use postProcess for thickness and color

Added classes in the GraphicsEx namespace. Broke out StrokeVertex to a
public class, as it was needed for the post processing, Made classes
Graphics, Fill and Stroke overrideable. More classes should have
privates turned to protecteds, but this is a start.
Adding GraphicsEx example

Adding a GraphicsEx example, but I am using FlashDevelop, so the project
structure is a bit different. Naturally, the examples should all have
the same structure, but I can't achieve that.

Sample includes a version of the Ripple UV Vertex shader together with a
TwoTextureVertexColorFragmentShader, creating an interesting effect by
placing the same glow texture ontop of eachother, animating it at
different speeds. Outside of the scope for the GraphicsEx demo, perhaps.
Performance improvements in Stroke class

Adding support for pre allocated vertex and indices buffers in
Stroke.buildGeometry .

On my PC, this gives a performance boost from 2100 to 1200 ms on very
large test _lines (15000 StrokeVertex objects in _line, yielding about
450000 vertices) If this boost works on mobile devices, I don't know, I
only have a PC to run the code on.
Redesigned code to prepar Stroke for a push request

Added a few comments, and hopefully this code (containing both old and
new versions) will be possible to push into the wild.
Merge pull request #55 from IonSwitz/master

Adding GraphicsEx APIs and Improving Performance for Stroke.buildGeometry()