Improved error message when encountering unsupported file types
Improved error message when encountering unsupported file types

Fixes #269.

bjornfor/nix,ehmry/nix,wmertens/nix,ysangkok/nix,ehmry/nix,aucampia/nix,rowhit/nix,shlevy/nix,vizanto/nix,ysangkok/nix,dtzWill/nix,dezgeg/nix,vcunat/nix,garbas/nix,NixOS/nix,shlevy/nix,aucampia/nix,ehmry/nix,pikajude/nix,peti/nix,joelmo/nix,wmertens/nix,offlinehacker/nix,tchajed/nix,puffnfresh/nix,rycee/nix,acowley/nix,tchajed/nix,layus/nix,layus/nix,offlinehacker/nix,shlevy/nix,bennofs/nix,joelmo/nix,ttuegel/nix,peti/nix,layus/nix,dezgeg/nix,layus/nix,acowley/nix,gebner/nix,dezgeg/nix,acowley/nix,dezgeg/nix,ttuegel/nix,wmertens/nix,puffnfresh/nix,gridaphobe/nix,joelmo/nix,bennofs/nix,pikajude/nix,vizanto/nix,zimbatm/nix,NixOS/nix,garbas/nix,zimbatm/nix,offlinehacker/nix,peti/nix,rycee/nix,garbas/nix,tchajed/nix,ysangkok/nix,ehmry/nix,rycee/nix,gridaphobe/nix,peti/nix,pikajude/nix,rycee/nix,ehmry/nix,NixOS/nix,dtzWill/nix,vizanto/nix,puffnfresh/nix,bjornfor/nix,gridaphobe/nix,vcunat/nix,shlevy/nix,puffnfresh/nix,garbas/nix,garbas/nix,bennofs/nix,bjornfor/nix,ehmry/nix,rowhit/nix,peti/nix,vcunat/nix,ttuegel/nix,dtzWill/nix,NixOS/nix,gebner/nix,ttuegel/nix,zimbatm/nix,aucampia/nix,vcunat/nix,joelmo/nix,offlinehacker/nix,zimbatm/nix,bennofs/nix,gridaphobe/nix,layus/nix,NixOS/nix,acowley/nix,vizanto/nix,shlevy/nix,dtzWill/nix,dezgeg/nix,gebner/nix,aucampia/nix,rowhit/nix,dtzWill/nix,rowhit/nix,wmertens/nix,bjornfor/nix,rycee/nix,tchajed/nix,gebner/nix