remove old-IE rawSetX and rawSetY code from GenomeView
consolidate genomeview track layout code, switch to using track tops for vertical scrolling instead of changing the top of the scroll container
add track menu item for pinning tracks to the top of the view, still needs layering fixes
pinning refinements, added pinning underlay
make the vertical scrollbar not overlap the pinned region
tweak pin underlay shadow
add a few comments to GenomeView
add 15px of padding below the pinned tracks
revert topSpace treatment back to what it was originally
port track pinning to run on the pub/sub system
Merge branch 'pin_track'