Make 'allFlags' return 'NoFlag' by default.
Make 'allFlags' return 'NoFlag' by default.

Otherwise this field is by default printed as 'all: False' instead of '-- all:'
in the config file. Ideally, we'd like to print the commented default value.

thomie/cabal,lukexi/cabal,gridaphobe/cabal,Peaker/cabal,edsko/cabal,enolan/cabal,x-y-z/cabal,ghc-android/cabal,rimmington/cabal,Helkafen/cabal,rimmington/cabal,gbaz/cabal,kosmikus/cabal,valderman/cabal,typelead/epm,kolmodin/cabal,plow-technologies/cabal,randen/cabal,headprogrammingczar/cabal,fugyk/cabal,ian-ross/cabal,martinvlk/cabal,trskop/cabal,corngood/cabal,bennofs/cabal,plumlife/cabal,sopvop/cabal,lukexi/cabal,seereason/cabal,x-y-z/cabal,triplepointfive/cabal,thomie/cabal,seereason/cabal,martinvlk/cabal,Heather/cabal,trskop/cabal,eric-stanley/cabal,randen/cabal,kosmikus/cabal,gbaz/cabal,mydaum/cabal,headprogrammingczar/cabal,fugyk/cabal,valderman/cabal,triplepointfive/cabal,bennofs/cabal,eric-stanley/cabal,mydaum/cabal,christiaanb/cabal,ian-ross/cabal,sopvop/cabal,Helkafen/cabal,plow-technologies/cabal,themoritz/cabal,mightybyte/cabal,garetxe/cabal,mightybyte/cabal,anton-dessiatov/cabal,garetxe/cabal,themoritz/cabal,Heather/cabal,mmakowski/cabal,themoritz/cabal,ghc-android/cabal,plumlife/cabal,christiaanb/cabal,enolan/cabal,beni55/cabal,corngood/cabal,kolmodin/cabal,beni55/cabal,thoughtpolice/cabal,sopvop/cabal,edsko/cabal,mmakowski/cabal,thoughtpolice/cabal,Peaker/cabal,anton-dessiatov/cabal,typelead/epm,gridaphobe/cabal