Makefile with dynamic linking and some other stuff

Dynamic linking for MinGW, symbol stripping for release builds and experimental win64 support.
I've managed to build a MinGW-w64 64bit executable but it crashed.
Not able to test cross-compiling with dynamic linking on, should work in theory.
With DYNAMIC_LINKING=1 people don't need to compile libpng, freetype, zlib, etc.
Just use the binary and devel(mingw) packages from http://www.libsdl.org/ and start building Cataclysm.
This makes MinGW into the minimalist solution it was meant to be and will encourage new people to start using it. Using MSYS is an option of last resort which can be avoided.
I've tested this using a fresh MinGW installation plus the SDL packages.
And yeah, this is starting to sound like some cheesy commercial.