Bugfix : use ambient light from the sun when SH maps are not used
Tigher fit of light extent
Tweak light attenuation.

Doesnt really change the look of the light but reduce their extent.
Add a new option for high-definition textures.
Improve flying mode
Improve flying mode, part 2
Merge pull request #1303 from leyyin/master

Fix some bugs in the online screens
Create the directory where resized textures will be cached.
Fix bullet assertion failure
fixed identing, added comments, corrected spelling, etc.
Minor correction to patch from konstin.
Minor changes to the grand prix editor
Almost rewrite of GrandPrixData::reload()
small corrections in grand_prix_data.cpp
try increasing light count
Allow to toggle dof off
Potential fix for #1305
Use a more efficient screen to view conversion

Also use the opportunity to use UBO where possible.
Use smaller textures when HD textures option is disabled. Generate them if they are not already in the cache directory.
Merge remote-tracking branch 'remotes/upstrem/master' into hd-textures-option