switch fill to fill_color in bokehjs
Squashed 'subtree/bokehjs/' changes from 4ef354b..8b12fbf

8b12fbf change fill property to fill_color
6ef50ba tune some parameters to try and improve tearning issues on spectrogram

git-subtree-dir: subtree/bokehjs
git-subtree-split: 8b12fbf80aee3e89b21f8bc4c5738aecb5df612a
Merge commit 'aed37b8886e78eeb9eb7f061192abe39e439b083'
update built js