Merge Pages and Tomes (AS3 implementation)

"Tome" now combines the functionality of Tome and Page. Tome instances
contain microtome schema-specified data, like Pages did before, but can
also contain an arbitrary number of other child Tomes of any type.
Merge Pages and Tomes (py implementation)
updated parser & python code generation

page Foo {...} -> Tome Foo {...}

Untyped Tomes are allowed as specified Tome properties
updated as3 code generation
updated python tests
updated as3 tests
update README with new syntax