fix the OpenGL offscreen rendering a bit

Change-Id: I1f11cdff0de48e3281a58aec9ea37a78c637195e
more 3D rendering fixes

Change-Id: I8943355de1b9440104e0281131fb0df3fc599bb4
add codes to Rectangle::render()

Change-Id: I4a86de032970bfd9cba6270e8e6c6a00e550d74e
add the codes for rendering text in class:GL3dRenderer

Change-Id: Ia36e042d30afcc13be5fa3452123ae0778217877
add codes to Text::render()

Change-Id: I894cbb42b795f1adee41694011fa2477f87850f0
add api for render non rouded bar

Change-Id: I16bb4ec77cccf0ff9e73f02e13288562004eb5bc
add code to call the bar api

Change-Id: Icee44999c175b5d964ebd51c56e9a1585506e036
fix wrong shader names

Change-Id: Icd2d219446cdf78c4be97f96e38c9e4b174f9ddd
add some missing pieces from the 2D renderer to the 3D one

Change-Id: I9933a429f42f8a350a88aa77514f934560ed58f3
fix matrix generation

Change-Id: Id31caa16dfe0d0f23cf07589053233e9b311d02f
add new window that contains OpenGL context

Change-Id: I81ce3581942d03785809d728b6b54b570899bcdc
avoid linking against the OpenGL libs when only using the window

This lets us avoid to link libsclo against all the OpenGL libraries and
only link against libvcl_opengl. Only code actually using the context
will need to link against the OpenGL libs.

Change-Id: Ia47f4c651702a7fb8517073cda6fb113e7e26e50
let us use the new OpenGLWindow

Change-Id: I5cbab0aa1707513b62f7a9958fac013b3beb2dcb