store: refactor the fncache handling
put all the fncache file writing and reading in
the same place.
#!/bin/shrm -rf ahg init acd aecho foo > foohg ci -qAm0chmod +x foohg ci -m1hg co -q 0echo dirty > foosleep 1hg up -qcat foohg st -Aecho '% validate update of standalone execute bit change'hg up -C 0chmod -x foohg ci -m removeexechg up -C 0hg uphg st