Add option --new-branch

Update tests for Mercurial 2.0

Whitespace cleanup

Prettify command help with reST

Minor cleanup

Don't break on RepoError

Amongst others a not reeachable remote repository may throw a RepoError
which now gets handled similar to Abort errors. They are logged and - if
configured - trigger a call of the alert tool. Subsequent the command
continues to run.

Add example alert tool for Linux desktop systems

Unify alert and merge tool configuration

!!! This changes the autosync command interface !!!

KISS. Now there's only one way to set an alerter tool, using the option
alert in section autosync of an HGRC file. Same thing for the merge
tool: it is defined in autosync->merge. This benefit here is that this
clearly distinguishes the merge tool configuration for the autosync
command and ohter commands which use ui->merge or HGMERGE to get the
merge tool.

This change also fixes a parameter type error when calling the alert
tool.

Fix extension name in license header

Update doc

Make test script less verbose

This reduces the risk to fail in different Mercurial versions just
because some status messages differ slightly.

Initial commit