Added very basic ICCCM compliance (and reformatted the code).

 - SmallWM will now draw the Pixmap that a window wishes for its icon
 - SmallWM now uses XGetWMIconName to get the real icon name
 - Set better ICCCM compliance as a future goal
Added backup for XGetWMIconName.
Fixed a program-crashing bug.

If the user clicks on an icon, and tries to move it, SmallWM will crash.
Avoid crashing by doing nothing if the user tries to move an icon.
Added window snapping.
Reformatted the code and commented more heavily.