Added three demo widgets and a widget template to documentation
Cleanup of itemmodels.py
Fix crash in scatterplot when domain does not have class var.
Fix crash in scatterplot when domain does not have class var (right file).
Added Majority classifier widget.
Added Save/Load Classifier widgets.
Added pyqtgraph to requirements.txt.
Retain attribute 'name' after Table transformations.
Do not set 'disabled' property on 'widget'.
Refactor Data Sampler widget.
Fixed commit method in Data Table widget (fixes #59).
Reader for a very simplified txt format with or without any header row
File widget reads .txt files
Store escaped table name in SqlTable.
Sql parser for columns, FROM, and WHERE part of sql.
Get column types from sql.
Parser test.
Fix a bug when parsing selects with only one column.
Refactor SqlParser.
Add from_sql constructor to SqlTable.