Auto merge of #9128 - adrianheine:patch-1, r=jdm
Auto merge of #9128 - adrianheine:patch-1, r=jdm

Add autoconf to build dependencies

`autoheader` from `autoconf` was necessary for the build on my system.

<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/9128)
<!-- Reviewable:end -->

jimberlage/servo,ConnorGBrewster/servo,paulrouget/servo,DominoTree/servo,nnethercote/servo,dsandeephegde/servo,fiji-flo/servo,paulrouget/servo,KiChjang/servo,KiChjang/servo,canaltinova/servo,thiagopnts/servo,notriddle/servo,thiagopnts/servo,rnestler/servo,CJ8664/servo,DominoTree/servo,szeged/servo,canaltinova/servo,saneyuki/servo,canaltinova/servo,dati91/servo,avadacatavra/servo,larsbergstrom/servo,nrc/servo,KiChjang/servo,avadacatavra/servo,pyfisch/servo,paulrouget/servo,larsbergstrom/servo,DominoTree/servo,mattnenterprise/servo,saneyuki/servo,dati91/servo,steveklabnik/servo,nrc/servo,anthgur/servo,larsbergstrom/servo,mattnenterprise/servo,szeged/servo,mattnenterprise/servo,splav/servo,canaltinova/servo,emilio/servo,mattnenterprise/servo,steveklabnik/servo,peterjoel/servo,peterjoel/servo,rnestler/servo,pyfisch/servo,nrc/servo,cbrewster/servo,peterjoel/servo,cbrewster/servo,eddyb/servo,eddyb/servo,cbrewster/servo,peterjoel/servo,mbrubeck/servo,pyfisch/servo,dati91/servo,emilio/servo,saneyuki/servo,jimberlage/servo,canaltinova/servo,dati91/servo,jimberlage/servo,nnethercote/servo,notriddle/servo,thiagopnts/servo,emilio/servo,nrc/servo,eddyb/servo,notriddle/servo,jimberlage/servo,saneyuki/servo,eddyb/servo,paulrouget/servo,thiagopnts/servo,splav/servo,peterjoel/servo,saneyuki/servo,cbrewster/servo,emilio/servo,pyfisch/servo,pyfisch/servo,notriddle/servo,CJ8664/servo,jimberlage/servo,paulrouget/servo,rnestler/servo,eddyb/servo,upsuper/servo,dsandeephegde/servo,szeged/servo,DominoTree/servo,DominoTree/servo,nrc/servo,CJ8664/servo,splav/servo,szeged/servo,upsuper/servo,szeged/servo,SimonSapin/servo,mbrubeck/servo,sadmansk/servo,sadmansk/servo,upsuper/servo,emilio/servo,splav/servo,steveklabnik/servo,jimberlage/servo,splav/servo,splav/servo,dati91/servo,upsuper/servo,CJ8664/servo,notriddle/servo,ConnorGBrewster/servo,KiChjang/servo,CJ8664/servo,szeged/servo,upsuper/servo,CJ8664/servo,avadacatavra/servo,CJ8664/servo,thiagopnts/servo,pyfisch/servo,dati91/servo,nrc/servo,mbrubeck/servo,larsbergstrom/servo,anthgur/servo,CJ8664/servo,paulrouget/servo,DominoTree/servo,emilio/servo,pyfisch/servo,jimberlage/servo,saneyuki/servo,avadacatavra/servo,splav/servo,sadmansk/servo,mbrubeck/servo,eddyb/servo,canaltinova/servo,dsandeephegde/servo,thiagopnts/servo,paulrouget/servo,sadmansk/servo,peterjoel/servo,nnethercote/servo,ConnorGBrewster/servo,fiji-flo/servo,KiChjang/servo,SimonSapin/servo,paulrouget/servo,anthgur/servo,steveklabnik/servo,mattnenterprise/servo,DominoTree/servo,upsuper/servo,larsbergstrom/servo,peterjoel/servo,rnestler/servo,rnestler/servo,thiagopnts/servo,anthgur/servo,DominoTree/servo,pyfisch/servo,canaltinova/servo,steveklabnik/servo,dsandeephegde/servo,ConnorGBrewster/servo,szeged/servo,sadmansk/servo,nnethercote/servo,avadacatavra/servo,fiji-flo/servo,cbrewster/servo,dati91/servo,emilio/servo,pyfisch/servo,paulrouget/servo,KiChjang/servo,larsbergstrom/servo,nnethercote/servo,SimonSapin/servo,pyfisch/servo,notriddle/servo,splav/servo,avadacatavra/servo,KiChjang/servo,notriddle/servo,SimonSapin/servo,sadmansk/servo,avadacatavra/servo,saneyuki/servo,rnestler/servo,cbrewster/servo,ConnorGBrewster/servo,mbrubeck/servo,peterjoel/servo,avadacatavra/servo,nnethercote/servo,upsuper/servo,saneyuki/servo,saneyuki/servo,larsbergstrom/servo,nnethercote/servo,splav/servo,ConnorGBrewster/servo,fiji-flo/servo,mattnenterprise/servo,DominoTree/servo,dsandeephegde/servo,mbrubeck/servo,dsandeephegde/servo,paulrouget/servo,anthgur/servo,fiji-flo/servo,emilio/servo,eddyb/servo,rnestler/servo,KiChjang/servo,notriddle/servo,dsandeephegde/servo,mbrubeck/servo,saneyuki/servo,canaltinova/servo,dati91/servo,KiChjang/servo,anthgur/servo,peterjoel/servo,peterjoel/servo,mattnenterprise/servo,szeged/servo,fiji-flo/servo,anthgur/servo,steveklabnik/servo,fiji-flo/servo,cbrewster/servo,emilio/servo,szeged/servo,szeged/servo,nrc/servo,SimonSapin/servo,cbrewster/servo,SimonSapin/servo,eddyb/servo,jimberlage/servo,upsuper/servo,notriddle/servo,mattnenterprise/servo,sadmansk/servo,anthgur/servo,larsbergstrom/servo,fiji-flo/servo,nnethercote/servo,nnethercote/servo,DominoTree/servo,SimonSapin/servo,notriddle/servo,nnethercote/servo,steveklabnik/servo,splav/servo,ConnorGBrewster/servo,jimberlage/servo,larsbergstrom/servo,mbrubeck/servo,rnestler/servo,sadmansk/servo,thiagopnts/servo,dsandeephegde/servo,larsbergstrom/servo,ConnorGBrewster/servo,KiChjang/servo,SimonSapin/servo,emilio/servo