Merge pull request #77 from janezd/master

Add space after widget boxes in gui, fix some specific widgets
Temporarily skip unit test.
Add travis configuration.
Only run widget tests if PyQt is installed.
Skip sql tests if psycopg2 is not available.
Merge pull request #79 from astaric/travis

Add travis configuration.
Added missing packages and package data entries in setup.py
Changed few labels and PEP-restructured the code.
Merge branch 'master' of github.com:biolab/orange3
Comment to add_origin, removed previous todo mark.
- kNN classifier from scikit moved to script part (orange/classification)
- usage of default scikit learn imputer class to handle NaN; (optional) replace with Orange imputer when implemented.
- added Mahalanobis distance.
Removed long description (too verbose and obvious).
Merge branch 'master' of github.com:biolab/orange3
Moved EntropyMDL code from to widget.
Merge pull request #85 from janezd/mosaic

Changes in Mosaic GUI
Follow redirect for OSX application template download.
Updated 3rd party packages included in Orange3 OSX application template.
join_contingency for Entropy discretization: 3x-10x speedup.
Travis: install only .whl requirements.
Use explicit ordering when querying column types.