Objectives:
* Make it possible to add items to toolbars without having to have all
toolbars know about the items in advance
* Make it possible to specialize an existing tool and have it be used
instead of the base implementation
Approach:
* Tools are named using a path-style category/id/ext system, making them
selectable, the latter component being used to differentiate extended
tools from their base classes, but is ignored during selection
* Toolbars have ToolGroups, which include or exclude tools by category or
category/id, and order them by promoting and demoting selections of
tools by category or category/id
Future:
* Add a way to place available but not yet placed tools in an "overflow"
group
* Add a mode to ToolGroup to make the tools a multi-column drop-down style
list with labels so tools with less obvious icons are easier to identify
- and probably use this as the overflow group
Change-Id: I7625f861435a99ce3d7a2b1ece9731aaab1776f8
Mostly as a demonstration of how easy this is with MWExtensionNode.
The icon was chosen with the following criteria:
1. Recognisable (the ankh is quite common in popular culture, right?)
2. Doesn't look idiotic to academics (I've consulted an Egyptology
PhD and they can confirm it's not the glyph for penis)
3. Renders well at <16x16
That said it does look a little like a stick man...
Bug: 43118
Change-Id: I9f9e8af501401866bfeecf0eec3690a705fbd4db
