Fixed a bug in NodeDictionary.remove.
Added full support for Value.status, Value.type and Value.toVirtualString.
Renamed Type to TypeInfo, and introduced the struct Type.

Basically Type is a struct that contains only a const TypeInfo*.
Previous uses of const Type* (in particular, the type field of
nodes) have now be replaced by Type.

This helps hiding away the details of how the type field of a node
is actually stored. It will ease the writing of alternative memory
models.
Updated for the new Abstraction/CodeArea schema.
Output debug data for stack trace generation.
Added Parser.oz and PEG.oz in the compiler functors.
Updated for the new opcodes that create structures.
Removed the restriction on \n in strings, atoms, etc.
Update for the renaming of OpPatternMatch to OpPatterMatchX.
Inverted the two bodies of setupExceptionHandler.
Reviewed CodeGen: simpler and generates more efficient bytecode.
Updated for the forks of mozart2-library and mozart2-compiler.
Base -> Base.ozf.
Added the filesystem sublibrary of Boost.
Added Init.oz and URL.oz to system functors.
Added more system modules.
Fixed a bug in Namer about multiple symbols for the same var.
Major review: much better handling of the Base env and BootMM.
Added the binding of <Base>.Base to <Base>.
Big changes to make Base and some others work in Mozart 2.

This commit is actually a manual merge of the code we wrote by
bits for Mozart2. That history is not included here because the
branches were in two separate repos with no common ancestor commit.
It's just safer not to introduce multiple roots in this repo.

The history of these commits is still available in the main repo.
The code that is now here was located under directory lib/.