MAJOR CHANGES

-Renamed S…(SVersion and whatnot) to SDL…
-Moved SDLVersion to the top of the script to make it easier when
there’s a new SDL version (but can also work with any other SDL version)
-Relocated some variables
-Added SDLPicked: captures the main name of the picked SDL
-Removed $RET_haveSomePi. It’s useless
-Function check_for_pi exits immediately upon knowing that it’s running
in an improper device
-Made it clear as to why I really want to have function aptget_stuff
-Removed useless “else” condition in function check_for_libfiles
-Edited some strings
-Edited some comments
-Fixed bugs that prevented the script from running