started moving buttons to part-specific toolbars

uses another QSplitter within path view
connect pathtoolbar to pathtoolmanager

also, remove righttoolbar from mainwindow
removed lefttoolbar

deleted first & last buttons, moved renum to path toolbar
update to 20px icons, rearrange toolbar layout
new AI files for addseq icon
New tool button for add-origami-part
added a label to part toolbar

updated SVG button appearance
data-svg file
updated appearance of data-svg AI source file
Merge pull request #16 from cadnano/buttondev

Buttondev