Added "+ Objective" to sections

"+ Objective" will jump directly to create objective, and then after
successful creation, will create a join between the new objective and
the original section.
Tweaked "+ Objective" workflow

- Moved "+ Objective" link after "+ Object"
- Moved "map new objective to section" information from the form to the
title of the modal
- Added the section description as the default objective description
Fixed if_equals not passing the proper context stack
"+ Objective" launched from the multitype selector will now use the section's description as the default
Fixed issues with the "+ Objective" modal

- Now uses JSON.parse to ensure that object params are uncached
- Added json_escape helper to properly escape strings for JSON parsing
Merge pull request #345 from reciprocity/feature/add_objective

Added "+ Objective" flow to sections "+ Object"