[lively-kernel] Debugger now available in all worlds

[Christopher Schuster]

Hi,

There is still a long way to go, but everyone interested in debugging Lively 
can now use the built-in cross-browser debugger in three different ways:

1. Ctrl+Shift+D / Cmd+Shift+D
   keyboard shortcut to debug the selected code fragment

2. World Menu > Debugging > Debug Morphic Scripts
   enables setting breakpoints in the object editor
   with "debugger" statements

3. World Menu -> Debugging -> Prepare system for tracing/debugging +
   World Menu -> Debugging -> Start global debugging
   uses method instrumentation to maintain stack information
   with a slight performance overhead

If any of these three methods is used, unhandled exceptions will open a 
debugger window instead of showing a red box.

Any feedback regarding bugs and feature requests is appreciated.

Happy debugging,
Christopher

PS: Integration with the test runner is on the way and coming soon.