[FEATURE] Added a LowLevel Gerrit:Update script

sometimes you couldn't execute gerrit:update
because of fatal problems in your code because of missing
changesets for example. This commit adds a way to fix
update and fix such an incomplete state through:

./Packages/Application/Famelo.Gerrit//Scripts/gerrit update

Change-Id: Ia35e958aa24d56fb3f600b0037e994b1b30b6f67