bundle2: print debug information during bundling The bundler class is now feed with an ui object and use it to transmit data about the bundling process.

bundle2: add ability to write to a file to the test Next changesets are about improving debug output during bundling. We won't be able to simply bundle to stdin in this case. The bundle2 stream would be interleaved with debug output.

subrepo: factor out Git version check to add doctests Followup to 6a2acb0d9352::e5641536e4d5.

contrib: add "hgperf" command to measure performance of commands easily Newly added "hgperf" command repeats "dispatch.runcommand()" for specified Mercurial command and measure performance of it in the same manner of "contrib/perf.py" extension. Users (mainly developers) can examine performance of the target command easily, without adding new entry for it to "contrib/perf.py" extension.

grep: exit loop immediately, if matching is found in the file for "hg grep -l" Before this patch, internal function "display()" of "hg grep" is not efficient for "-l"/"--files-with-matches", because loop is continued, even after the first matching is found in the specified file. This patch exits loop immediately, if matching is found for "--files-with-matches". In this case, "before is None" is equal to "opts.get('files_with_matches')".

grep: use "found" instead of "filerevmatches" examination for efficiency Before this patch, internal function "display()" of "hg grep" stores whether matching is already found or not into the dictionary "filerevmatches" by "(fn, rev)" tuple as the key. But this is redundant, because: - "filerevmatches" is local variable of "display()", so each "display()" invocations don't affect others - both "fn" and "rev" (gotten from "ctx" argument) are never changed in each "display()" invocations Then, "filerevmatches" should have only one entry at most, and "(fn, rev) in filerevmatches" should be equal to "found". This patch uses "found" instead of "filerevmatches" examination for efficiency.