Bring event names in line with upstream bootstrap

Bootstrap creates a show/hide event prior to showing/hiding an element and a
shown/hidden element after showing/hiding it. Except, in older versions of
bootstrap this wasn't implemented for tooltips and popovers. We ended up
implementing this functionality itself, but unfortunately we used our own names
for the events, and additionally re-used THEIR event names for our own
purposes. Bootstrap has now fixed this issue, leading to infinite recursion
in our code. This applies a more consistent event naming.
Bring monkey-patched show in line with upstream.
Only monkeypatch if bootstrap is old.
Avoid some errors that occur if the popover never opened.
refs #466: display smaller image dialog box when editing description
refs #466: edit description changes to match mockup
Refactoring of code that prevents popup closing

This uses the fact that aloha won't deacivate the editor if it has
.aloha in its hierarchy. Of course marking something with class=aloha
brings about styling baggage, so that had to be reset.
Append popovers to the body of the document instead.

This moves the popover out of the editor area, which means mouse clicks and
keypresses does not cause selection-change events in your editor. Unfortunately
this only works with bootstrap>=2.3, but at the moment it is not broken for
oerpub so this is an acceptable outcome.
Mark click events with preventDefault

This indicates to higher level event handlers that the link plugin has already
handled the click event. Specifically, it prevents github-book from opening it.
refs #466: made image selection more like mockup in image dialog box
broadsword renaming of popover to overlay.

This avoids adblock+.
refs #466: if image is too big, we resize it to fit the available real estate.
refs #466: tighten css for description hover effect
Add settings modal to semantic blocks for adding a custom class
refs #466: use max-height css attribute to control image size in image dialog box
Merge remote-tracking branch 'origin/master' into ticket-359
refactor semantic blocks dependency structure
Merge remote-tracking branch 'origin/master' into ticket-359
refactor semantic blocks dependency structure (continued)
fix font awesome