Add basic window resizing handling.
Fix bugged SDL static library build.

- I fixed the DLL exports earlier for .lib files but didn't commit changes.
- The other problem was SDL disabling stack resizing (by overwriting _chkstk()) and allocation static stack size (as it's size wouldn't change inside a shared library, which is not the case for static libraries). I can't think of a reason this was done other than virtually almost none performance improvement (at least on PC).