Fix issue #62 : Graph drawing - wrap filter names. Reorganised filter layout to put pins at the top overlays at the bottom. Filter wrap width is adjustable via view/menu keyboard/mouse shortcuts.
Modified keyboard shortcuts so that -/+ keyboard combos are consistent with mouse wheel keyboard modifiers

git-svn-id: http://graph-studio-next.googlecode.com/svn/trunk@254 c2f33eb2-41b2-391d-4cb4-d9d0608729ba