Reference types expect receiving LockedObjects when setting vals on
keys.  In the python code, the method ensure_locked_obj handles this
before passing back to LockedObjects.  Will have to make equivalent
method in Java code.
Added several additional missing container methods (len, del, etc.).
Never should be serializing from parent delta of single map or single
list: container generates these itself.
To accommodate having maps/lists hold value types for internal
reference containers, needed to extend generic's signature to include
type when de_waldoified.
User-facing locked container variables wrap an internal container
variable inside a reference.  This commit, defines the reference that
holds the internal container.
Added a single threaded map container variable to implementation
(without deserialization).  To do so, had to create a map variable,
which holds a reference to an internal map container.
Ensuring that any java value that is written to a container gets
wrapped as a locked object first.
Added a test to ensure basic, single threaded map setting and getting work.
Added tests for map to delete val on key and to check contains.
Added test infrastructure: can now run all library tests in a row and
view their output.