[PATCH] minor change to mailer.py for subject formatting

Hi,

This is a minor change to the mailer.py script often used with the
post-commit hook.

The purpose of the change is to make it possible to dynamically insert
the directory name of the repository in the subject text. Simply it
replaces the term REPONAME in the commit_subject_prefix setting with
the base directory name of the repository. For example if your
repository is in `/path/to/test1` and `commit_subject_prefix =
[svn-REPONAME]`, then the subject of commit emails will be prefixed
with `[svn-test1]`

This simplifies the configuration because multiple repositories can
reuse the same mailer.conf file.

[[[
   When formatting commit email subjects, replace REPONAME in the
commit_subject_prefix setting with the basename of the repository
directory
   ]]]

Regards,
Janos

--
Janos Gyerik
http://www.janosgyerik.com/
https://twitter.com/janosgyerik/