Removed OS X version check

It didn't work correctly and .plist should set minimum OS version to run on
Added auto-release pools to decrease memory fragmentation on older OS X like 10.5 or 10.6
Availability of game controller API is now determined on runtime
Removed all code to support compilation using 10.4 SDK

10.5 is minimum version of OS X SDK to build. Deployment target can be 10.4 though
This reverts significant part of d061adf
Merge branch 'z_osx_clean' of https://github.com/alexey-lysiuk/gzdoom into osx