Docs: RestKit does not seem to ship with Appledoc binaries
Rakefile: Remove template path from appledoc invocation

With the template path included, docs refuse to build. By creating an empty folder, docs start to build but then fail with "Object template file 'object-template.html' is missing" error.
Merge pull request #1445 from paulmelnikow/building_docs

Fix 'rake docs' and related documentation