R1:8b304870c442

Use only the first line of update comment in revision history description

Summary:
More complicated updates deserves title and explanation.
This diff uses only the first line from comment in diff's description.
It also removes the truncating at 80 chars which looks as an error.

Test Plan:
var_dump(preg_replace('/\n.*/s', '', "abc"));
var_dump(preg_replace('/\n.*/s', '', "abc\ndef"));
var_dump(preg_replace('/\n.*/s', '', "abc\ndef"));
var_dump(preg_replace('/\n.*/s', '', "abc\ndef\nghi"))…