ok jamsek

This eliminates the previous performance cost by making 'got log -d' and tog diff view compute the diffstat while building the diff in a temp file like we do with 'got diff -d'. Also, keep the current 'got log -d' UI as per stsp's suggestion. ok stsp@

Like got log -d, add the switch to 'got diff' to display a diffstat of changes; as per stsp's suggestion, we always include diff output with the diffstat. Disabled in gotwebd (for now :) Includes tweaks from op@ ok stsp@

patch by Josiah Frentsos

Add new got_diff_blob_cb() implementation to compute added/removed line metrics for a given diff. This enables displaying a diffstat with 'got log -d'. As per suggestion from stsp, change tog diff view to display the diffstat by default. ok stsp@

ok landry@

The -h and -V/--version flags must be given before the command; with those flags the command is actually optional, but don't over-complicate the usage string with these nitpicks. ok/improvements stsp@

Similar to `git init -b`. Includes a change to `got import` behaviour such that "main" is no longer hardcoded by default; instead, we import to the branch resolved via the repository's HEAD reference unless `got import -b` is used, and only if HEAD cannot be resolved to a branch do we fallback to "main". includes fix plus ok from stsp@

ok jrick

Patch by Josiah Frentsos; ok kn@