Splitting fully upwind patches

@WilkAndy, I split your mega-patch into three separate patches containing source code, doco, and tests, respectively.  This makes it a lot easier for us to focus on the commits we need to review... I'm not sure if you will be able to merge this PR directly, but if you want to recreate essentially what I did, the commands are below:


```
cd $MOOSE_DIR
git reset HEAD~1
git add modules/richards/include/*/*.h
git add modules/richards/src/*/*.C
git ci -m"Fully upwind Richards flux. Refs #3252."
git add modules/richards/doc/*
git ci -m"Fully upwind Richards flux.  Adding doco for fully upwind Richards flux. Refs #3252."
git add modules/richards/tests/*
git ci -m"Fully upwind Richards flux.  Adding tests for fully upwind Richards flux. Refs #3252."
```