Add edit project capability to Projectify page

Clicking the P icon now brings up the projectify page.  From there you can
complete/uncomplete the task, edit the description or add/remove
contexts.

Also refactor the display of contexts so they are no longer hardcoded.
Ability to customize contexts has yet to be added.
Update documentation pages

Updated the features list on the home page and also edited and added
some quick formatting to the about/contribute pages to make them look a
bit nicer.
Fix bug when clearing contexts from project

Simulation steps:
-In the user home page, find project with at least one context
-Click the projectify icon next to that project
-Uncheck all contexts for the project
-Click "Save Project"

Problem:
Application dumps back to user home page, but contexts are not updated.
This is because the Project::getContextChanges method expects an array
and not a null value.

Resolution:
Add default value 'null' for the $inputs parameter and added code to
convert a null value to an empty array.
Merge branch 'project'
Fix typo in anchor href on home page

The link to the CONTRIBUTE page was pointing to contributing instead of
contribute.  Fixed.
Fix typo on home page
Turn off debug mode in live environment

Yeah.... let's not enable that...
Add 'add task' button to projectify page

Add button to add tasks to a project and jQuery code to add the DOM
elements on click.

Submitting of these tasks not implemented yet.
Add ability to add multiple subtasks (incomplete)