bring the gradient rendering down into SalGraphicsImpl & unx backend

Change-Id: Ia5d5e7d996b4a8818e73f3f741907ff9224f93da
remove useless define

Change-Id: I3033748cac045cd6e9595fadc84c65b21128b39d
move defines to the top of the file

Change-Id: Ia76fd2b1f9d7a9056425c760320f6b87965a2012
implement gradient rendering method for windows backend

Change-Id: I894b14d97227d695f5cfc5e13958413c36295d7d
remove unused function

Change-Id: I990e53f55093affa0da1878d1cdd46f6b1c6a99c
fix indentation

Change-Id: Ia61988f94a2cce9aefe1b48159a1bf1884be70f2
don't include the win version of svsys directly

Change-Id: I21f9443ad847ab07c3e25e6004d2133148db7f03
make it possible to select the OpenGL rendering on windows

Change-Id: Id60b8121a890e6d1f46bd671549ac681f42b7660
no check before delete and move to intializer list

Change-Id: Ib6e50f863db1a64dc42ed4313a009abe4932ce3f
that stuff seems to be totally unused

Change-Id: Ice7bc99fc5f3d26ced1b7cd5a1dbf29b0e635471
this configuration option is totally unused

Change-Id: I6057dfff10d8c776080df2de0b259bd401cd7fb7
add configuration value for VCL OpenGL backend

Change-Id: Ie23e31bec68e6f5ae3aab6ff5d6f19df5c2c9242
use configuration value for OpenGL backend

Change-Id: I18aa0a19a625b2a64d26adacaa139c9bf734dc9b
move that variable out of the constructor init list

We might delete it a few lines later again if we select the OpenGL one.

Change-Id: I08bac1b65bbae02f4f1dd149f484132f84dbc371
use constructor init list

Change-Id: I0344bdbd1e5643f8de1ce336caec21a3e789d4ca
vcl: Implement basic SalGraphics methods for OpenGL backend

Change-Id: Iade3960c38f0de5594bc98e535450abcf88e9a6d
extract shaders from source code

Conflicts:
	vcl/opengl/gdiimpl.cxx

Change-Id: Ifbb55e58e0854cc491703b8ca8d8e582741a9bd9
vcl: Some fixes to the OpenGL impl

Change-Id: I58466142e0a47beb892e10113c1bc34d5ac3abcd
vcl: Add methods to get size of OpenGLSalGraphicsImpl

Change-Id: I7eecbc236db12fb9453384985245eb5ca781e0f5
vcl: Update OpenGL context before drawing

Change-Id: I7575881d8d9a2026a74692ca562a340231d946bd