This is quite a big commit which adds an experimental text script to
UI bytecode compiler. The compiler is still under heavy development
and can and will be under heavy changes, so use with caution.
In addition I added the old file browser for unix like platforms
back into the demo. At the moment it only supports windows but
the only part of the file browser that is platform dependend
is the directory content loader which should be easy to implement
in other platforms as well.
While dividing previously spared me from a lot of work and problems
it is probably best to have everything working for every or as many
platforms as possible. Some platforms fail to provide good ways
to support everything (e.g.:X11 does not have pixmap clipping with
different width/height or alpha-blending) but all OpenGL demos
outside allegro (needs some additional work) should be able to run.
Previously it was not possible to control the visibility or rather
the transparency of all render vertex buffer output. For that to
change another settings was added to zr_convert_config to control
the visibility. To achieve the same result as previously it is now
required to fill that property with 1.0f. To make all GUI element
as a whole more transparent a value between 0.0 and 1.0 can be
selected with 0.0 being completely hidden and 1.0f completly
visible.
