Add `image_label2rgb`
Fix: Add setup.py which adds data file to the build
ENH: Add some checks on the inputs.
TST: Add tests for image_label2rgb
DOC: Change more examples to use `image_label2rgb`
API Change: `image_label2rgb` changed to `label2rgb`.

The name change reflects a switch in the argument order (and makes the image an optional argument).
Fix `RequiredAttrs` definition.

The example in python's descriptor tutorial creates a singleton so multiple,
instances share the same attribute. This update fixes the issue based on [1].

[1] http://stackoverflow.com/questions/8718052/where-does-a-python-descriptors-state-go
Fix parameter name in docstring
Add infrastructure for conneting plugin output to a viewer.
Add example of connected viewers/plugins
Dock plugins to image viewer.
Fix sizing of PlotPlugin
Display title in docked plugins
Add smart window-layout for multi-viewer display
Add mock pyqtSignal to try to get Travis to build
Second attempt to get Travis to pass
Third attempt at getting Travis to build
Accidental deletion
Add attributes to Mock object to fix Travis build
Fix PySide compatibility for signal defs