[hack] Use find.ml in the sqlite index buidler instead of shelling out
[hack] Use find.ml in the sqlite index buidler instead of shelling out

Summary:
simpler, share code, and use the standard filters.

while I'm here, ignore all .hg and .git directories

Behavior change: symlinks are not followed, matching the rest of hack server.

Differential Revision: D18143530

fbshipit-source-id: cb76539461c3814559570671e90d7c546164d37c

samwgoldman/flow,facebook/flow,mroch/flow,mroch/flow,samwgoldman/flow,mroch/flow,samwgoldman/flow,samwgoldman/flow,samwgoldman/flow,samwgoldman/flow,facebook/flow,facebook/flow,facebook/flow,mroch/flow,mroch/flow,facebook/flow,mroch/flow,facebook/flow,facebook/flow,mroch/flow,samwgoldman/flow