closes #15
style changes to insertionitem and fixed the fact that Qt5 uses QTransform for QMatrix from Qt4, close #14
fixed InsertionItem by adding a new subclass for the QGraphicsTextItem that intercepts events to get Qt.Key_Tabs as keyPressEvent doesn't get tabs for some reason, also added focus out handlings. closes #17
closes #18. fixed key error.  Added Key_Escape support and removal handling GC cleanup issue 'if parent is None: ...' code to InsertionItem
Merge pull request #16 from cadnano/buttondev

Buttondev
closes #20 typo
Merge branch 'master' into buttondev
added icon-label pref, started tool view