Support SVN 1.5 merge tracking in Revision Log view

[Javier Sanz <jsceballos@…>]

Starting with Subversion 1.5, the "svn log" command accepts a new option -g [—use-merge-history].
When used, the commands shows, for each of the changes which are merges, all the original changes that have been merged with it. It shows their full log entries: revision, date,author, and message.

Ideally Trac should support this too.

One possible way to show that info, is to nest a new table under each change that is a merge.

Something like this (suggested at trac-users mail list):

|| Rev || Date  || Author || Log Message                        ||
|| 100 || ././. || xyz    || merged bugfix #123 from stable     ||
||     ||       ||        ||                                    ||
||     ||       ||        || ||Rev||Date||Author||Log Message|| ||
||     ||       ||        || ||98 || ...||xyz   ||bugfix #123|| ||
||     ||       ||        || ||97 || ...||xyz   ||clean-up   || ||

Additionally, a new checkbox could be provided to enable this feature, named something like "Include merged revisions".

[cboos]

See #1492.