OpenGLContext stopped to support multisampling under linux.

glTF rendering needs to have a context with multisampling
so it also became broken.

Regresssion from:
07c0396ab9c94be5af392827f56f0d91551f3e25

This breaker change was made assuming getVisual{Info}() is always
called after the SystemChildWindow is already created, but
generateWinData() is run as part of the new child window creation.
It's aim to choose the best visual / FBConfig which potentially support
multisampling.

Change-Id: Ic881c6769260b5eaa9fed2552eca882191f6c56d
(cherry picked from commit d85b975667dfba755b9c952a2b8030a7f33bba66)
Do not limit graphic cache size setting to 256 MB.

Change-Id: I62835721225cc39dd9fd5131843d57497794be95
(cherry picked from commit 356006b4967fad26c7edd2126860abf01206fdbd)
Don't use a hard coded limit for size based auto swap out.

Now the graphic cache settings shows the real memory usage for
the users, so we can bequeth the decision of the limit to them.
Default is 200 MB.

See also:
dbdacc73ae154237314d599194cc686bd738a9bf

Change-Id: I463d31254f6f1836e1584d5acd692f38a97bfe39
(cherry picked from commit a87b1b07b91960601c7f39e2b40eba8ad50b1667)