Working guides at multiple zoom levels.
Axis working on ar downsample
Adding spread shader
Making unused serverdatasources non-fatal
Restoring accidentally removed plot
Ending merge
Only imports abstract_rendering if executed against.  Updated error message
Merging master...
Deferred load of abstract-rendering to use time on server.
Merging master
Formatting and spelling.
First working US Census AR example
Fixed issues with negative start/end ranges
Merging master after bokeh.charts
Merging master after bokeh.charts...part 2
Merge pull request #755 from ContinuumIO/feature/abstract_rendering_guides

Feature/abstract rendering guides