Squashed all buildscript/jenkins changes into one unified commit
Only applied rune's fix in #2 in addition to that (dunno if #3 should be applied)
cuchaz's pr is merged upstream so that we don't need to cherry pick that any more
Lastly, please create a new branch off the ref of the head branch (liachmodded:pick-3) and just push that branch to this repo instead of merging this pr.
Lastly, please create a new branch off the ref of the head branch (liachmodded:pick-3) and just push that branch to this repo instead of merging this pr.