Merge pull request #1186 from lakkatv/xmb

(XMB) Prevent list highlighting
Change video_gl_context to video_context_driver
Rename g_settings.video.gl_context to g_settings.video.context_driver
Refactor gfx_ctx_init_first
Expand gfx_context with prev/next functions
Add commented out fallback code in case driver init fails -
as soon as we have fixed the init function in DRM/KMS context
driver we can reconsider enabling this.
Update other gfx_ctx_init_first calls
Start moving context driver variables to struct that gets
allocated and bound to driver.video_context_data - begin
with GLX context driver first
(menu) fixes menu not being properly hidden after loading/saving a state
Merge pull request #1187 from aliaspider/master

(menu) fixes menu not being properly hidden after loading/saving a state
(DRM KMS) Convert DRM KMS context driver over
(SDL context driver) Convert over
(Wayland context) update/convert
(gfx_context) Fix warnings
(OSX) Use CGLUpdateContext for OSX 10.7 and up
Update SDK
(Lakka) Display ON/OFF switch