Implement variadic argument support functions.
Add missing copy method for pointers.
Fix pointer construction.
Structure libraries as libraries.
Update sandbox.dart for new APIs.
Use correct setters when storing data in memory.
Default-initialise offset to 0 (null is not a sensible integer to use later).
Use correct-sized methods for loads as well…
Fix copied-and-pasted typo (memory is allocated in bytes, not bits).
Compare with null, not 0, to check for uninitialised object.
Fix method names in types-test.dart.
Fix pointer-related bugs identified by test-types.dart.
DartC object comparisons now return a DartC int but Dart control statements expect a bool.  Make sure that the compiler is always producing a bool.