Multi controller version.

2 controllers can be plugged and used.
confJoyTool is a tool to configure joystick mapping. Just start it and follow instructions. The xml file joysticks.buttons written by this tool must be in current directory when starting snes9x because it will look for ./joysticks.buttons .

I made many changes to make this working fine. I changed all makefile to use non-decprecated rules. g++ is the only compiler used and I had to change some code to make it compile. Compilation is a bit longer because of g++ use.

All unused file for rpi have been deleted. Maybe some headers are also useless but grep tell me they are still used (but maybe inside #if #endif blocks).