Add rerender event to all image loads in MWExtensioNode.
MWHieroNode's implementation of onParseSuccess is now the same as
its parent so can be deleted.
Change-Id: Iaa4999372f1ba88a7bdf1490fc3f8640af77ceae
Create getter for extensionsName which is overriden by
MWAlienExtensionNode.
Also removed angle brackets around Alien title as the inspector
already has an angle bracket icon, and a '<' close button.
Change-Id: Ice8c5d73ed621f8e585b5f372788666f8c5aeb50
onUpdate was renamed to update. Also neither event was
actually implemented so have just removed them.
Change-Id: Iaae1661a99f97272fa42c71223fc2cb832d50c66
MWMath and other simple extensions all behave in a similar way, e.g.
<tagname>Foreign syntax</tagname>.
This creates a base class that should make supporting such extensions,
and editing their contents in a plain text box, very simple.
Change-Id: Icc0acb33fe32704f71dacb552d9dfa3142eaef2b
