Replace `TracGuideToc` with `UserGuideToc` on bh wiki upgrade. Refs #555.

A regression introduced in [1496686], which fixed unintended replacement of `TracIni` macro markup, also broke the ability to intentionally replace macro markup. `_do_wiki_rename_links` now supports replacement of macro markup by using the macro syntax when specifying the word to replace (i.e. wrapping the !CamelCase word in double brackets).


git-svn-id: https://svn.apache.org/repos/asf/bloodhound/trunk@1514197 13f79535-47bb-0310-9956-ffa450edef68