Have configure check for SDL2
Initial attempt
Necessary slash
Make win32 save dir relative to steam common dir
Use relative save directory if STEAM defined

The linux one appears to work. The others will be tested shortly.
Fix windows local GetSavePath

Appears to work correctly on windows with these changes.
Make linux local save dir relative to exe

Before it was relative to cwd. Also did some refactoring.
Locate save folder based on AppInstallDir

Also, some patching up of the existing save folder functions.
This is all only tested on Linux as of this commit.
Update install w/ aclocal, remove unneeded exports
Merge branch 'SteamApi' into SteamSavedir2
Adding basic support for game controllers
Vastly improve experience when using primarily keyboard/gamecontrollers to move through menus
Clean up first_buttonwait_mode_frame, make it a bool instead of a counting int
Fix OSX local saves dir, and make local saves dir a compile-time option
Improve comments and enable game controllers by default
Merge Steam Save Dir support
Merge branch 'master' into screen-readers
Fix OSX compiling mess, reducing number of configure env vars that need to be set!
Merge branch 'master' into screen-readers
Make screen reader support optional