Fixed createWar so that createDist does not need to be run first

I noticed that the `createWar` function that I added about a month ago has a slight problem. If one doesn't run `python build/build.py dist` before `python build/build.py war` the `build/vnu` folder does not get created, which leads to an error when the script attempts to create the temporary `war` subdirectory.

	Traceback (most recent call last):
	  File "build/build.py", line 1124, in <module>
	    createWar()
	  File "build/build.py", line 726, in createWar
	    os.mkdir(warDir)
	OSError: [Errno 2] No such file or directory: './build/vnu/war'