Make useless whitespace adjustments.
Move JS debugger into separater object, make core library properly remove or insert nodes, and not just hide them.

For interactive node adjustment (i.e. previous behavior), the debugger object could still be used.
Hide node.js module declaration from non-node.js environments (UAs).
Remove debug output from Python version.
Make Python version pass all the unit tests, fix several bugs.
Add separate HTML and XML output functions to Python version.
Add the PHP writer file, which was sadly forgotten.