cleanup

- fix possible crash in conc (but it's still an ugly hack)
- fix noob usage of strcmp
- flag some memory leaks (it would be nice, if the author(s) would clean
   up the mess himself)
- fix crash in substr
- whitespace cleanup

there are plenty more memory leaks in command.cpp - for example, every
goto in cubescript does not clean up anything

source/src/stream.cpp

@@ -337,7 +337,7 @@ bool preparedir(const char *destination)
         dirs.add(newstring(dir));
         copystring(dir, parentdir(dir));
     }
-    
+
     loopvrev(dirs) if(!createdir(dirs[i])) return false;
     return true;
 }