use d3.time.scale() when x is time
fix for javascript date format
Support for y axis date and a test plot.
fixes after rebase
PEP8
BUG: make patch collections pan & zoom
Added logscale and an example.
Merge pull request #11 from jkfurtney/time_scale

Time scale support for x axis
Add basic support for imshow.
add colorbar to test image
Merge branch 'pr/1'