GUIWindowSystemInfo optimization
[OverlayRenderGL] Fix corrupt pixels in graphical subs

On Pi you can see a corrupt line of pixels on bottom and right edges of subtitle bounding box.
This is due to using a subregion of a texture (due to the power of two rounding) and not ensuring
the texture coordinates are inside the valid pixels.

The easy solution is to use NPOT when available (always on GLES) and then the clamping works
(as well as saving memory).
fixed: PrepareSQL in ViewDatabase.cpp was missing an argument.
fixed: cosmetics
Merge pull request #3115 from stupid-boy/GUIWindowSystemInfo

GUIWindowSystemInfo optimization
updated addon helpers

in particular, we now handle buildsystems which output several add-ons
properly. real life case; screensavers.rsxs
[WIN32] added a xbmc-config.cmake.win32 for windows
[WIN32] added xbmc_find_path to find paths recursively
[WIN32] removed prepare_addon_environment(). this is done in the prepare-env step now.
move to addon helpers. fits better and avoids duplication for win32
[cmake] add lto support again
[cmake] fix tgz package and set zip as default cpack_generator
Merge pull request #3126 from cptspiff/fix_multiaddon

updated addon helpers
GUILabelControl optimization
Merge pull request #3114 from stupid-boy/GUILabelControl

GUILabelControl optimization
Merge pull request #3116 from popcornmix/gfxsubcorrupt

[OverlayRenderGL] Fix corrupt pixels in graphical subs
[rbp/omxplayer] Support both analogue and hdmi audio

Thanks to stupid-boy for original implementation.
[3D] Support switching to 3D resolutions

Include matching 3D flags (SBS/TAB) in the score of a resolution to switch to, to enable switching to 3d modes.
Also remove the old code that treated 3D modes differently when assigning a score.

I've also added a small weight to higher multiples of the desired framerate, so if display supports 30, 60 and 120Hz
and the video is 30fps then 30 will now be chosen rather than 120. This reduces the overhead of rendering the gui.
[confluence] Use animated gif as a cheaper working spinner
[rbp/omxplayer] Do we need discontinuity handling?

So far I've not seen what this is needed for and it does cause problems for some files.