v0.6.0-alpha DRIFT STONES

• uncertainty and error bit propagation in expr and all nodes
• Testing quality and propagation rules
• Test graphs for nodes and other high-level functionality
• Test nodes for those graphs
• Tabular output on spectrum and histogram nodes
• Gen node for test patterns
• Refactoring of Datum
• Utility nodes - e.g. roidq for generating an ROI from DQ bits
• Output enhancements
  • Gradient node can export to PDF
  • Annotations (e.g. text labels) are now drawn on the painter at
    high res, and have been refactored hugely
  • Annotations use thickness zero by default (the Qt "cosmetic" thickness)
• PCT detector node
• ROI negation and refactoring of operators
• roiexpr node for composing ROIs using expressions
• Crude band depth node (needs work)
• A lot of bug fixes and regression fixes