Merge pull request #147 from enthought/refactor/image-plot

Refactor image plot

Author: corranwebster

CHANGES.txt

@@ -9,6 +9,8 @@ New features/Improvements
  * Replaced chaco.base.bin_search by numpy.searchsorted-based routine for
    5x speedup and remove use of zip in chaco.base.arg_find_runs in favour of
    column_stack for 10x speedup in bad cases. (PR #263)
+ * `ImagePlot` refactored to clarify transformation applied to images and allow
+   easier reuse of transformations in subclasses. (PR #147)
 
 Fixes