Automatically resize Graphite URLs to fit their frame
Tune frame refresh behavior.

This fixes the following issues:
- when editing the URL, the frame should only be refreshed when the input is
  "complete" (change event)
- the refresh button should work (for both graphite&non-graphite URLs)
Set menu panel background color to white again.

(It was black text on black background)
Merge pull request #41 from prometheus/graphite-resizing

Resize graphite frame graphs