Remove all trailing spaces

No real changes, just clean up sources by removing trailing spaces from
all the non-generated files.

This should hopefully avoid future commits mixing significant changes
with insignificant whitespace ones.

docs/wine/changes.txt

@@ -9,4 +9,4 @@ for wxWINE is in place and that all that has to be done to get
 wxWINE running is to make WINE work as Win32. No joke intended.
 
   Robert Roebling
-  
+