gitignore and improved install script

No more reboot required (which is quite annoying when testing different versions).
I'm asking for sudo within the script so the commands within your own directory won't be run as root. Only the necessary actions will be run as root.

It works for me, but please let me know if something is in your environment so I can make adjustments when necessary.

I also added a gitignore file for the created directories by the installer.