Pts v0.5.0

Pts has reached 0.5! 🎉This is a milestone release with many updates and improvements.

New features:

• New homepage
• New and improved documentation
• Live demo code editor
• Pts.quickStart mode and updated demo code (see Getting started for details)

Breaking changes

• Pt's cross2D renamed to $cross2D
• Util.warnLevel property becomes a function Util.warnLevel( ... )
• Removed Circle.toInnerRect (use Circle.toRect instead)
• typescript: Bound class moved into Pt module
• typescript: All type alias moved into Types.ts file
• typescript: updated version to 2.9.2

Bug fixes

• fix IE and mobile css bugs
• fix devicePixelRatio bug when it's less than 1.
• demo updates and minor bug fixes