Mpldatacursor

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1/5/2014
Enabled keyboard shortcuts by default. "d" hides/deletes visible
annotation boxes, while "t" toggles interactivity.

1/5/2014
Added the ``props_override`` option to customize the x,y location where
the popup is displayed without subclassing or monkey-patching
mpldatacursor.

1/5/2014
Fixed bug with bar plots and made width, height, etc be passed in to
the formatter function for Rectangle artists.

1/2/2014
Added basic support for allowing datacursors to pop up on hover.

12/29/2013
Made the ``bbox`` and ``arrowprops`` arguments use the mpldatacursor
defaults as a "base". Therefore, specifying something like
``bbox=dict(alpha=1)`` will result in a yellow, opaque box with rounded
corners instead of a blue, square box.

12/22/2013
Added a workaround for a bug in the OSX backend that causes a segfault.

12/17/2013
Alessandro Impellizzeri switched things to use relative imports for
compatibility with python 3.x.

11/15/2013
Made x,y position of annotate snap to the displayed x,y values
Thanks to megies for the bug report and suggestion!

10/7/2013
Fixed bug in line interpolation. Kudos to dand-oss for the catch.

8/20/2013
Bugfix for images with matplotlib 1.3.

7/30/2013
Refactored mpldatacursor into multiple files.

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7/18/2013
Ehsan Azar added rate-limit to avoid multiple calls and resulting
"animation effect" when multiple artists are selected.

7/15/2013
Added support for displaying non-scalar z-values (e.g. R,G,B). Kudos
to Ivan Panchenko for the suggestion.

7/13/2013
Fixed major bug in image handling. Incorrect z-values were being
displayed for non-square images.

6/22/2013
Added hiding and disabling functionality. New methods:
datacursor.hide(), datacursor.enable(), and datacursor.disable() as
well as datacursor.enabled property Kudos to Joe Louderback for the
suggestion.

6/22/2013
Added ``point_labels`` kwarg and functionality. New ``point_labels``
kwarg that allows labels for the "subitems" of an artist (e.g. points
in a ``Line2D``) to be individually labeled.

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5/19/2013
``pcolor`` and ``pcolormesh`` support. Added support for "z" info for
``pcolor`` and ``pcolormesh`` plots.

5/18/2013
``contour`` and ``contourf`` support. Added support for "z" info for
``contour`` and ``contourf`` plots. Unfortunately, these artists can
only be picked when an "edge" is clicked on, so ``contourf`` support is
less than ideal.

3/9/2012
Removed redundant ``template`` and ``offsets`` kwargs in favor of the
``foramtter`` kwarg.

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3/4/13
Added ``datacursor`` convenience function, which automatically connects
a datacursor to all plotted matplotlib artists.

2/28/13
Made draggable datacursors a kwarg option instead of a separate class.

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2/21/2013
Initial commit in git

1/22/2012
Many minor updates.
See http://stackoverflow.com/revisions/4674445/3

1/12/2011
Initial version.
See http://stackoverflow.com/revisions/4674445/1