This class may be used for sending email messages for Subversion repository
activity. There are a number of different modes supported, and SVN::Notify is
fully subclassable, to add new functionality, and offers comprehensive content
filtering to easily modify the format of its messages. By default, A list of
all the files affected by the commit will be assembled and listed in a single
message. An additional option allows diffs to be calculated for the changes and
either appended to the message or added as an attachment. See the with_diff
and attach_diff options below.