Merge branch 'release/0.3.2'
views/ui: Add more comments
views/ui: Add a set of widgets
views/ui: Refactor search bar
views/advanced: Use UI widgets
Import labeledSlider jQuery UI extension

Written by Ben Olson.

See: https://github.com/bseth99/jquery-ui-extensions
views/ui: Define a search-form-text-input-widget

This means that we don't have to wrap the widget parameter of
search-form-widget-row in a col-md-6.
js/main.js: Include 3rd party libraries first

Otherwise they are undefined when we want to use them in main.js.
Implement a pI input slider

This uses a slider to input isoelectric points to search by on the
Advanced Search page.
util: Horizontal separators in comments
Bump release version for '0.3.3'
js/main.js: Apply linter fixes to labeledslider

Add some of the recommendations from ./scripts/linter/javascript.sh.
js/main.js: Increase pI slider step to 1
Merge branch 'release/0.3.3' into stable