Added prax uninstall command
Added prax uninstall command

As raised by #46 there was no way to easily uninstall Prax. Until
now :)

dsager/prax,Kriechi/prax,Kriechi/prax,ychaim/prax,ysbaddaden/prax,ysbaddaden/prax,Kriechi/prax,dsager/prax,Kriechi/prax,ysbaddaden/prax,ysbaddaden/prax,dsager/prax,ychaim/prax,dsager/prax,ychaim/prax,ychaim/prax