Added a list style editor page to the formatting dialog.

Added a list style editor page to the formatting dialog.
Added a style organiser dialog, which can be used to browse
for and apply styles and can be limited to show one of
the three style types, or all three.
Added a font name cache since it's an expensive operation
that's used frequently by the rich text dialogs.
Added ability to switch off tooltips for new dialogs
(off by default). Improved the previews. Pressing tab or shift-tab
at the start of a list item now demotes or promotes the item.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@42116 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775