* src/RelLib/_Note.py: import const from MarkupText module
* src/MarkupText.py: use actions instead of widgets on the interface;
new helper functions
* src/Editors/_EditNote.py: move widgets out to glade; implement new
MarkupText buffer interface; use uimanager/toolbar for formatting
* src/glade/gramps.glade: edit_note update
svn: r8292