Fixes Issue #15 by converting the topic partials to HAML

Pretty much a straight conversion from ERB to HAML, although I made a
few corrections, like linking the topic name in the list view to the
show page along the way.

I didn't correct some existing deficiencies like form errors not being
displayed or search status not being populated into the page since that
seemed to be out of the scope of the issue.
Remove list_members_path and get member sidebar working

It turns out that Rails 3 is pickier about matching content_for to
yield and wants them to both either be a symbol or a string.

And the list collection action was no longer present in the members
controller but was still in a sidebar and the routes filed, so I
removed it.