Port of PPSSPP to the OpenPandora

[ptitSeb]

I added an option in menu to activate/deactivate the "Alpha Hack" mentionned in another thread. The OpenPandora use an SGX GPU, so this hack is makes some games run really faster.

Here is the diff.

Lumine & Tales of Eternia are running much faster with this activated. Tales of Eternia has some black artifact unfortunatly on figh sequence with this, but it's minor.

Also, on Pandora forum, there is a report from user "itami" that those games are runing well:

Airu de Puzzle
Densha De Go! Pocket - Chuuousen Hen
Lets Golf (no sound)
Pirates of the Caribbean: at world's end (about 50% speed)
Sid Meier's: Pirates (no sound)
Samurai Dou 2 Portable
Shichida Shiki Training Unou Tanren Portable
Zero Pilot - Daisanji Sekai Taisen