A different fix for record crash, use pixfufs instead of canvas text in markers,...

A different fix for record crash, use pixfufs instead of canvas text in markers, use leftmost_frame instead of querying canvas coords when scrolling (speeds up canvas scrolling somewhat), remove old include, remove first_action_message and some other unused methods.

git-svn-id: svn://localhost/ardour2/branches/3.0@5108 d708f5d6-7413-0410-9779-e7cbd77b26cf