add liberator.hasExtension for testing for the presence of a given FF extension
add liberator.hasExtension for testing for the presence of a given FF extension

Kjwon15/dactyl,airodactyl/airodactyl,madand/pentadactyl-pm,paretje/vimperator-labs,nathyong/dactyl,zklinger/vimperator-labs,seanmorton/vimperator-labs,nathyong/dactyl,madand/pentadactyl-pm,5digits/dactyl,Kjwon15/dactyl,moonshadow/dactyl,Evidlo/vimperator-labs,Kjwon15/dactyl,Kjwon15/dactyl,Quicksaver/vimperator-labs,airodactyl/dactyl,zklinger/vimperator-labs,nullren/vimperator-labs,derenio/vimperator-labs,seanmorton/vimperator-labs,stemar94/vimperator-labs,derenio/vimperator-labs,airodactyl/airodactyl,airodactyl/dactyl,invl/dactyl,stemar94/vimperator-labs,airodactyl/dactyl,5digits/dactyl,Kjwon15/dactyl,nathyong/dactyl,5digits/dactyl,moonshadow/dactyl,airodactyl/dactyl,Kjwon15/dactyl,invl/dactyl,moonshadow/dactyl,5digits/dactyl,invl/dactyl,invl/dactyl,Sheile/vimperator-labs,madand/pentadactyl-pm,moonshadow/dactyl,madand/pentadactyl-pm,invl/dactyl,5digits/dactyl,Evidlo/vimperator-labs,nathyong/dactyl,madand/pentadactyl-pm,5digits/dactyl,mcarton/vimperator-labs,moonshadow/dactyl,invl/dactyl,moonshadow/dactyl,nathyong/dactyl,airodactyl/dactyl,airodactyl/dactyl,mcarton/vimperator-labs,nullren/vimperator-labs,Sheile/vimperator-labs,Quicksaver/vimperator-labs,paretje/vimperator-labs,nathyong/dactyl,madand/pentadactyl-pm