Merge from BOS, fix help

grep: speed up matching, and only return one match per line.

Use ui.write instead of print in debugwalk.

Add grep command. It currently searches all revs of every matching file. I'll change this soon so that it can still do this, but it will not be the default behaviour. Many options are unimplemented. There's only one output mode. Binary files are not handled yet.

Map long option names containing dashes to ones containing underscores.

Minor test-help fix

Fixed some synopsises in command help.

Added missing doc strings for two new debug commmands.

Adjust display and alignment of command options to match global options.

Clean up displaying help of global options, only one row per option.

Moved --cwd handling to a place where ui and exception handling already exists.

Allow --help and --version being used together.

Added options -h/--help.

Moved special handling of --version and no hg command from parse to dispatch. This allows e.g. 'hg status --version' to work.

Sort global options by topic: directories, ui, timing, other (and changed indentation to match command table)

run the doc/* through aspell.

Removed forgotten debug print statement from commands.py and tests.

Update tests

Fix a couple fencepost errors in hg log

Fix hg log -p

Show number of new heads when doing a pull

Add debugdata for dumping revlog revision data

Merge with MPM.

Fix a small corner of log behaviour. If invoked with no arguments in a subdirectory of the repo root, it should print the history of the repository as a whole.

Update hg log docs

Merge with BOS

Fix help output, and a few broken tests.

Merge with MPM.

Get patchbomb working with tip again.

Rewrite log command. New version is faster and more featureful. The original implementation of log walked backwards through history, which had terrible behaviour. It took several minutes to view complete kernel change history on a fast machine, for example. The rewrite uses a windowed approach to walk hunks of history forwards, while still giving results in reverse order. This reduces run time from five minutes to five seconds on my system. In addition, the rewrite uses our normal name handling mechanisms, so you can run a command like "hg log net/ipv4/**.c" and get a useful answer. It optimises for three different cases (no arguments, only files, and anything goes), so it performs well in all circumstances I've tested.