Version 0.4.0

* Add bookmark information to the statusline function
* Add command variants to open in a new tab
* `Hglog` command can take the same options as the command line
* New `Hglogexport` command can export a patch for a changeset from the log window
* `Hgrecord` command to selectively commit parts of the current file
* `HgPostCmd` custom autocommand for power users
* Bug fixes and improvements