Merge pull request #173 from mtwebster/actions-urls

Actions: Instead of %L, use %F for file paths, and %U for file URLs for
Pathbar:  Altered shape to wedge, improve styling
Tweak spacing between breadcrumbs
pathbar: Make DnD highlighting a bit more consistent with the standard
GTK highlight.  Calculate button X position better so spacing is better
across themes.
pathbar: Improve directory name spacing in the breadcrumbs chain,
reshape arrow a bit.
Make pathbar a bit narrower, pointier.  Play with style a little bit.
Remove selected folder boldface, and remove child displacement for
selected crumb (it's much too pronounced for the narrower path bar.
Fix pathbar width calculation a bit.
Pathbar - a little more tweakage of the layout
Pathbar - still more tweaking layout
More pathbar fixes
Increased breadcrumb height by 2 px, some more calculation tweaks
Make breadcrumb buttons look a bit more "buttony"