squirreledEditable declared in wrong scope

The idea is that squirreledEditable is a global variable, here limited to the
plugin scope by requirejs, that helps us out during the times when
Aloha.activeEditable is misteriously cleared. Moving it to plugin scope appears
to be the correct fix then.
Hide the sidebar. Fixes #350.
Strip off the <html> envelope.
Move preventDefault earlier in changeHeading

Any errors in later processing causes the browser to follow the link, because
it never reaches the preventDefault. If we're going to prevent the click from
following the anchor anyway, might as well do it first.
protect against Aloha.currentEditable being null upon heading changes.
refs #374: have ephemera remove the data-original-title attribute that bootstraps inserts for tooltips.
Merge pull request #31 from wysiwhat/oerpub-ticket368

Strip off the <html> envelope.
add comment
Merge pull request #26 from wysiwhat/aloha-update

Aloha update
Comment reason for excluding ephemera links.
Make the body background gray, avoid the white block at the bottom.
Merge pull request #28 from wysiwhat/toolbar-squirrel-issue

squirreledEditable declared in wrong scope
Merge pull request #30 from wysiwhat/oerpub-ticket350

Hide the sidebar. Fixes #350.
Place error divs over menu bar.
Let requirejs name the popover plugin instead of explicitly naming it.

Explicitly naming the popover plugin appears to trigger a race condition that
results in a namespace conflict. The issue appears to be that there is both
a directory named popover and a module named popover. The browser loads the
modules asynchronously. If the popover module has finished loading by the time
math, image or link loads, nothing bad happens. If the popover module has not
finished loading, it attempts to load it again, finds the popover directory
and attempts to load lib.js in that directory. By not explicitly naming
the popover module, it will be named popover/popover-plugin automatically,
which in turn resolves the namespace issue.

Refs #347.
Merge pull request #32 from wysiwhat/oerpub-ticket347

Let requirejs name the popover plugin instead of explicitly naming it.
Merge remote-tracking branch 'origin/master' into blocks

Conflicts:
	src/plugins/oer/assorted/lib/link.coffee
	src/plugins/oer/assorted/lib/link.js
Merge branch 'blocks' of github.com:wysiwhat/Aloha-Editor into blocks