Added new templates and changes in existing ones to support blogs for apps
Markdown for blog posts body
Fix: when updating the post id was missing from the form
Typos
Merge branch 'issue-720-pybossa-app-factories' into issue-687-app-blogs

* issue-720-pybossa-app-factories:
  New app factories url_for endpoints
Merge branch 'master' into issue-687-app-blogs

* master:
  Quickfix for SF logo like on pybossa repo (exceptional small direct master commit)
  Fix broken url_for
  Fix rendering for 500 page error
Small improvements in blog post template
Merge pull request #15 from PyBossa/issue-687-app-blogs

Issue 687 app blogs