store: use fast C implementation of encodedir() if it's available For a netbeans clone on Windows 7 x64: Encoding all paths in the fncache: Before: $ hg perffncacheencode ! wall 3.639000 comb 3.634823 user 3.634823 sys 0.000000 (best of 3) After: $ hg perffncacheencode ! wall 3.470000 comb 3.463222 user 3.463222 sys 0.000000 (best of 3) Writing fncache: Before: $ hg perffncachewrite ! wall 0.103000 comb 0.093601 user 0.093601 sys 0.000000 (best of 95) After: $ hg perffncachewrite ! wall 0.081000 comb 0.078001 user 0.062400 sys 0.015600 (best of 100)