enables wiki styles for wp description and activity
refactors so that content_tag is not used - causes error

I am not sure why this error occurs when the method is used within the contents of the work package overview page but it does
provides object for rendering to enable ###NUMBER rendering
differentiates between text and object for text rendering to enable attachment rendering
Merge pull request #1594 from opf/fix/wp_textile_rendering

Fix/wp textile rendering