Rreorganization and restructuring

Major reorganization of folder structure and refactoring of
RetroPie-Setup Script. This is a major update and is not compatible to
the previous versions of RetroPie installations.
Updated SD card script
Update basic.py

Fix error if .gngeo does not exist.
Update emulators.shinc

Retroarch: allow sdl again
Update emulators.shinc

Retroarch: enable udev
Update retropie_packages.sh

Add depen_retroarch
Update emulators.shinc

https://github.com/libretro/RetroArch/wiki/Input-drivers-in-Linux-without-Xorg
Updated URL of themes download
Merge pull request #333 from gizmo98/master

Minor improvements
Add missing reboot function
Merge pull request #334 from gizmo98/patch-2

Add missing reboot function
Minor fixes.
Fixed asplashscreen service script
Updated Theme Simple Script
Updated Theme Simple installation
Added Mednafen PCE Fast
Minor fix
Updated RetroPie-Setup Script mit Mednafen PCE Fast
Fixed segacd, sega32x configuration
Updated SAMBA configuration