fix computation of column in presence of TAB
fix computation of column in presence of TAB

fxfactorial/merlin,the-lambda-church/merlin,rgrinberg/merlin,fxfactorial/merlin,ocaml/merlin,fxfactorial/merlin,dra27/merlin,dra27/merlin,ocaml/merlin,the-lambda-church/merlin,ocaml/merlin,fxfactorial/merlin,rgrinberg/merlin,ocaml/merlin,the-lambda-church/merlin,dra27/merlin,rgrinberg/merlin,rgrinberg/merlin,dra27/merlin