add "end of" section comments to avoid confusion for skipped
add "end of" section comments to avoid confusion for skipped

Several times I and others have mistakenly added packages to
expected-haddock-failures instead of expected-test-failures
for example - hopefully these section end comments will be
agreeable and help avoid such problems.

I added for all the long sections but not yet for the shortest
ones (ie skipped-builds and skipped-profiling) though maybe
they should have them too for consistency.

mgajda/stackage,alanz/stackage,jonschoning/stackage,DanielG/stackage,Daniel-Diaz/stackage,int-index/stackage,mrkkrp/stackage,ethercrow/stackage,phaazon/stackage,wereHamster/stackage,clinty/stackage,michalkonecny/stackage,massysett/stackage,asr/stackage,christiaanb/stackage,garetxe/stackage,spencerjanssen/stackage,k0ral/stackage,creichert/stackage,Gabriel439/stackage,lwm/stackage,iand675/stackage,soenkehahn/stackage,stackbuilders/stackage,l29ah/stackage,judah/stackage,ygale/stackage,GregorySchwartz/stackage,meteficha/stackage,agrafix/stackage,lemol/stackage,fimad/stackage,marcinmrotek/stackage,peti/stackage,amcphail/stackage,nomeata/stackage,mpickering/stackage,brendanhay/stackage,athanclark/stackage,simonmichael/stackage,jaspervdj/stackage,Shimuuar/stackage,bartavelle/stackage,codedmart/stackage,mstksg/stackage,phadej/stackage,fpco/stackage