#38 resizeable obs dialog

[PhillipsOwen]

this addresses issue #38

Draft for now. i am not entirely impressed with the resize package i used,

[mbwatson]

it feels a little funny how it wants to stay centered, but it works pretty well. i noticed there are minConstraints and maxConstraints props in the react-resizable docs that might help control the size of the dialog.

[PhillipsOwen]

i just put a fix into the code to allow the obs dialog to expand beyond 600px.

also, i believe that the odd handle dragging behavior may be related to the dialog being moveable (no anchor point).