#199 more details about errors

[Brian Robb]

I'd like more details about errors.

"Cannot load windowstyle 'windowstyle.rws'" is not a
good error message.

"Cannot load windowstyle 'windowstyle.rws' - low
memory" is better.

Sphere should have something like: SDL_GetError()

Sphere_GetError() perhaps

Or maybe use perror and friends

The reason for this is, I had two songs load and play at
the start of my game, and they took up lot of memory
that my pc just can't handle at the moment, so even
loading small image files gave an error message, but the
LoadWindowStyle call was first, so made me think that
was broken, yet it worked in the editor, so remove the
load/play songs and it was fixed.

Better error messages are always a good thing though.
:)