Add ability to select project

When editing tasks, you can now select which project
the task belongs to through a select2 dropdown box.
Allow project selection to be cleared

Use the select2 `allowClear` to put a little x in the
select2 box to allow it to be cleared.
Add description to project dropdown

Since some projects may have similar names, let the first
line only of the description show up in the results.
Allow 2 lines in dropdown

On second thought, tighten up the text and allow up to
two lines of description.