[Gzz] 17th (jvk)

[Janne Kujala]

17th: irregular frame work

Implemented clipping at paper boundary of the tearaway parts by
using a paper mask (currently a 4x4 texture) in texture unit 1.

Added a border drawing option to IrregularQuad that works
by drawing each side three times (with perturbed position) and 
then the inside once, but 2 pixels larger in every direction.

The current scaling and positioning is as follows:
cs1 is used only for choosing the tearaway part ([-1,1]² in cs1).
w specifies the size of the paper as [-w,w]x[-1,1] (in cs2).
The ripples are fixed in cs2 ('border' parameter specifies amplitude).

Wouldn't it be better to also specify the vertical size 
([-w,w]x[-h,h] (in cs2)) for full control of scaling?
Currently the vertical (in cs2) frequency of ripples in a 
given screen size of a (whole) paper cannot be scaled. 

        jvk