use 4 space tabs in configure.py, warn on re2c missing
use 4 space tabs in configure.py, warn on re2c missing

purcell/ninja,sgraham/ninja,ikarienator/ninja,mdempsky/ninja,bmeurer/ninja,juntalis/ninja,automeka/ninja,Ju2ender/ninja,liukd/ninja,mydongistiny/ninja,sgraham/ninja,nocnokneo/ninja,maruel/ninja,nocnokneo/ninja,okuoku/ninja,colincross/ninja,mdempsky/ninja,jhanssen/ninja,syntheticpp/ninja,TheOneRing/ninja,mohamed/ninja,purcell/ninja,maruel/ninja,ctiller/ninja,fifoforlifo/ninja,rnk/ninja,yannicklm/ninja,kissthink/ninja,automeka/ninja,okuoku/ninja,kimgr/ninja,autopulated/ninja,fuchsia-mirror/third_party-ninja,dendy/ninja,dendy/ninja,ThiagoGarciaAlves/ninja,fuchsia-mirror/third_party-ninja,Qix-/ninja,nico/ninja,mydongistiny/ninja,okuoku/ninja,ndsol/subninja,LuaDist/ninja,ignatenkobrain/ninja,vvvrrooomm/ninja,jendrikillner/ninja,barak/ninja,Maratyszcza/ninja-pypi,sxlin/dist_ninja,ThiagoGarciaAlves/ninja,dabrahams/ninja,glensc/ninja,colincross/ninja,jsternberg/ninja,jendrikillner/ninja,moroten/ninja,LuaDist/ninja,kimgr/ninja,nafest/ninja,hnney/ninja,ignatenkobrain/ninja,lizh06/ninja,curinir/ninja,vvvrrooomm/ninja,jimon/ninja,martine/ninja,metti/ninja,ctiller/ninja,pathscale/ninja,dabrahams/ninja,bradking/ninja,AoD314/ninja,metti/ninja,Ju2ender/ninja,mohamed/ninja,iwadon/ninja,sorbits/ninja,autopulated/ninja,dpwright/ninja,dabrahams/ninja,tfarina/ninja,jimon/ninja,moroten/ninja,sxlin/dist_ninja,juntalis/ninja,jsternberg/ninja,nicolasdespres/ninja,guiquanz/ninja,fuchsia-mirror/third_party-ninja,pck/ninja,Qix-/ninja,ndsol/subninja,atetubou/ninja,metti/ninja,jendrikillner/ninja,sorbits/ninja,nocnokneo/ninja,nickhutchinson/ninja,dpwright/ninja,dpwright/ninja,AoD314/ninja,rnk/ninja,sorbits/ninja,dorgonman/ninja,liukd/ninja,chenyukang/ninja,curinir/ninja,guiquanz/ninja,sorbits/ninja,martine/ninja,mutac/ninja,bmeurer/ninja,Ju2ender/ninja,automeka/ninja,curinir/ninja,ikarienator/ninja,maruel/ninja,dendy/ninja,automeka/ninja,dpwright/ninja,juntalis/ninja,mutac/ninja,barak/ninja,TheOneRing/ninja,kimgr/ninja,dabrahams/ninja,nickhutchinson/ninja,ikarienator/ninja,dorgonman/ninja,colincross/ninja,ilor/ninja,chenyukang/ninja,ctiller/ninja,sgraham/ninja,Maratyszcza/ninja-pypi,hnney/ninja,hnney/ninja,mutac/ninja,jimon/ninja,hnney/ninja,chenyukang/ninja,fifoforlifo/ninja,mydongistiny/ninja,jsternberg/ninja,AoD314/ninja,AoD314/ninja,synaptek/ninja,syntheticpp/ninja,kissthink/ninja,ndsol/subninja,pathscale/ninja,mydongistiny/ninja,ilor/ninja,synaptek/ninja,atetubou/ninja,maruel/ninja,ThiagoGarciaAlves/ninja,pathscale/ninja,Qix-/ninja,yannicklm/ninja,rnk/ninja,vvvrrooomm/ninja,glensc/ninja,ignatenkobrain/ninja,yannicklm/ninja,nico/ninja,fuchsia-mirror/third_party-ninja,nicolasdespres/ninja,barak/ninja,tfarina/ninja,LuaDist/ninja,curinir/ninja,glensc/ninja,yannicklm/ninja,jendrikillner/ninja,mgaunard/ninja,drbo/ninja,nocnokneo/ninja,drbo/ninja,bradking/ninja,ignatenkobrain/ninja,glensc/ninja,martine/ninja,Ju2ender/ninja,TheOneRing/ninja,syntheticpp/ninja,mohamed/ninja,lizh06/ninja,nickhutchinson/ninja,sxlin/dist_ninja,mdempsky/ninja,jhanssen/ninja,rjogrady/ninja,ndsol/subninja,Maratyszcza/ninja-pypi,martine/ninja,rjogrady/ninja,Maratyszcza/ninja-pypi,ninja-build/ninja,kimgr/ninja,synaptek/ninja,jhanssen/ninja,pathscale/ninja,kissthink/ninja,tfarina/ninja,nafest/ninja,colincross/ninja,moroten/ninja,chenyukang/ninja,bradking/ninja,pck/ninja,vvvrrooomm/ninja,pck/ninja,mgaunard/ninja,iwadon/ninja,ninja-build/ninja,pck/ninja,drbo/ninja,iwadon/ninja,atetubou/ninja,Qix-/ninja,nafest/ninja,ilor/ninja,purcell/ninja,liukd/ninja,nico/ninja,dendy/ninja,juntalis/ninja,rjogrady/ninja,nicolasdespres/ninja,ctiller/ninja,jimon/ninja,jhanssen/ninja,rjogrady/ninja,mohamed/ninja,ikarienator/ninja,metti/ninja,dorgonman/ninja,nafest/ninja,sgraham/ninja,drbo/ninja,okuoku/ninja,fifoforlifo/ninja,bmeurer/ninja,nico/ninja,ninja-build/ninja,guiquanz/ninja,guiquanz/ninja,sxlin/dist_ninja,sxlin/dist_ninja,mgaunard/ninja,rnk/ninja,kissthink/ninja,ilor/ninja,purcell/ninja,autopulated/ninja,moroten/ninja,barak/ninja,mutac/ninja,liukd/ninja,nicolasdespres/ninja,synaptek/ninja,TheOneRing/ninja,iwadon/ninja,lizh06/ninja,bmeurer/ninja,jsternberg/ninja,mdempsky/ninja,sxlin/dist_ninja,mgaunard/ninja,sxlin/dist_ninja,atetubou/ninja,fifoforlifo/ninja,ThiagoGarciaAlves/ninja,ninja-build/ninja,autopulated/ninja,syntheticpp/ninja,dorgonman/ninja,LuaDist/ninja,tfarina/ninja,nickhutchinson/ninja,lizh06/ninja,bradking/ninja