show/hide section content

using Bootstrap Collapse plugin
extract fragment id, show this element and scroll to it on page open
moved show/hide link text swap to event handler
adding comments above main code paths
only show pre-footer if it has content
changed to "Show"
style changes on label resource within a topic section
removing top margin from .section
need some additional bottom margin between .activity list items
styles to support positioning 'edit summary' link beside topic title
Adding 20pixel right padding for IE11 scroll bar glitch. It will allow future workarounds based on browser features and browser versions as well.
recompiling less source
Installation of modernizr
fix: Wasn't loading the library, removed ".js" in config.php
Changing the tag button into tag input, so then show_confirm_dialog in /lib/javascript-static.js will work properly. Affecting quiezes or places where confirmation dialog was shown.
remove opacity from hidden section

opacity and z-index values apply stacking contexts to the elements they are applied to. Stacking contexts are applied to a single root HTML element; child elements are confined to an order within this stacking context. Elements with the same stacking order are stacked according to appearance within the HTML. This was affecting the 'hidden' topic sections and the pop-up edit menus; they had similar stacking orders.
make label activity extend to full width of container
Merge branch 'refs/heads/bug-hidden_sections_overlaying_edit_menu' into develop

Conflicts:
	sourcemap-moodle.json
	style/moodle.css