fix wiki controller tests
fix svn repository controller tests
* unfortunately there are still two implementations
of #stylesheet_link_tag in the rails source code,
the new asset pipeline way and the old way. one
prepends "/stylesheets/" the other "/assets/".
chili's Hook classes included the old helper
module which generated the old path. this commit
should fix that, so you can put project specific
css files under "/app/assets/stylesheets"  (don't
forget to add the file to the "config.assets.precompile"
list)

* make the base.html layout file more descriptive