Do not guess variable types for sql tables by default.
type_hints is an Orange domain.
Avoid error when trying to send a selection of sql data.
Merge pull request #106 from lanzagar/scatterplot

Avoid error when trying to send a selection of sql data.
Adapted tests for SqlTable guess_values.
Class value indexes should not be hardcoded as variables can be
recycled.
Merge pull request #108 from markotoplak/sqlopen

SqlTable: feature value guessing option, type_hints are domains.
Normalize negative indices.
Paint Data widget refactor/rewrite.

Now using pyqtgraph instead of orangeqt.
Added some docstrings.
Constant time boolean evaluation of SqlTables.
Add option in Sql Table widget to enable domain guessing.
Refactor (cached) __len__ for SqlTables.
Merge pull request #109 from ales-erjavec/paint-data

Paint data widget rewrite
Group lines in parallel coordinates.
Use logger instead of prints.
Fix display of curves in parallel coordinates plot.