Cleanups to load_menu_game
Merge pull request #729 from lakkatv/lakka

(Lakka) Store the content icons in the category to save ram
Setup main_entry and environment_get for proper building of
argc/argv for console/mobile ports with non-conformant argc/argv
input values
(GX) Build fixes/style nits
(GX) Add new code for correcting argc/argv - doesn't work yet
(PS3) Starts working with new argc/argv building - only
broken usecase right now is Core Selection - we'll have to
mess directly with argc/argv for fixing that one - pretty
similar issue to the one on the Wii
(PS3) Fixed Core selection
(PS3) Cleanup - this can go now
Have to comment out turbo button functionality again for RARCH_CONSOLE
(GX) Move platform_gx over to new argc/argv system
Fix some dubious code in frontend/frontend.c.
(Lakka) Add callbacks to tweens, and fade the in menu when possible