XAML-Math v2.0.0

Although a major release with certain formally breaking changes, these changes should hopefully not break any normal usage of the library (if the user code doesn't implement own IElementRenderer).

Changed

• (Breaking!) Avalonia: rename AvaloniaBrushExtensions to AvaloniaExtensions.
• (Breaking!) WPF: rename WpfBrushExtensions to WpfExtensions.
• (Breaking!) IElementRenderer is now required to implement a new method, RenderLine (required for the new \cancel* commands).

Added

• jlm_msam10.ttf font with a lot of new characters, thanks @Orace, that closes the following requests:
  • angle, measuredangle, and square symbols are not rendered,
  • An unsupported command \geqslant.
• New commands: \cancel, \bcancel, \xcancel (partially addressing issue #349), thanks @Orace.

Fixed

• #409: Exception on empty matrix row.