Fix crash when printing unresolved closure/itbl
Let "lcc" maintain its own package database

The front-end compiler now no longer use the GHC API --make mode and
instead works like "ghc -c".  We also now use our own package
database.  This avoids issues due to mismatched identifier names.

Core libraries are now in the "libraries" directory and no longer
under the tests directory.  Building the core libraries is currently
handled by a shell script instead of Make, because we do not yet
accurately track dependency information.
Port *.Read modules to new directory structure.