update jquery ui to add draggable

they stopped numbering their files too
first pass at resizeable side panes

drag the shadow (weird but works)
the change is temporary - should at least be saved
i kind of like it resetting on collapsing/showing panels, tho
style the panel sizers

use a circle icon (kind of a punt) instead of shadow as handle
place them on the notebook column
add a sizing bar that appears when dragging
remove "fake left column"

it was breaking resizeable panels
and doesn't seem to be needed anymore
put limits on sizing of left and right panels

closes #624, almost
we just need to decide how to make the change permanent
print error message on unhandled rejection for non-chrome

fixes #570
if notebook load fails somewhere after the gist part, don't keep trying

we were going into a death loop on safari because of some random other
incompatibility in our code

for #809
remove obsolete performance log

it was bombing on safari
fixes #809
port a6e30b0,16cb0ce from develop
bump VERSION
add NEWS
make panel sizing bar transparent instead of hiding it when inactive

fixes #802
tweak sizer positions and make sizing grid responsive to window resizing

fixes #803
tweak left side panel resizer pos
open/hide side panels based on size

size 1 <=> hidden
otherwise shown

fixes #801
add panel-resize event and handle it in scratchpad

fixes #728
add bugfix comment; fix version number
tweak sizer bar styles
Merge branch 'hotfix/1.1.2'