Christian Ebert <blacktrash@gmx.net> [Wed, 23 Jan 2008 12:31:41 +0100] rev 349
Implement handle and hook for external callers
Allows external callers that do not use the command line to
pass current hg command to keyword extension.
This implementation might change in the future, if wrapping
of patch.diff is possible to the effect of avoiding external
handles.