Changes

Changes from Mercurial (hg http://isabelle.in.tum.de/repos/isabelle/ default)

provide src/Tools/Demo as example for system component with Isabelle/Scala tool;

Changeset 79058:f13390b2c1ee by wenzelm: provide src/Tools/Demo as example for system component with Isabelle/Scala tool;
The file was added	`src/Tools/Demo/README.md`
The file was added	`src/Tools/Demo/etc/build.props`
The file was added	`src/Tools/Demo/etc/options`
The file was added	`src/Tools/Demo/etc/settings`
The file was added	`src/Tools/Demo/src/demo_tool.scala`
The file was modified	`NEWS`
The file was modified	`etc/components`
The file was modified	`src/Doc/System/Scala.thy`