Improved spa2 to handle ACT-R modules
Add ACT-R declarative memory module to spa2
Add spa2 system for LHS matching and RHS convolution
Added ability to fake packages on import.

- This is used in creating the docs, since Sphinx is in cPython
  and can't do the Java imports.
Fake package system no longer needs dummy tree.

- Setting `__all__ = []` made `from pkg import *` work
Changed sys.path in Sphinx conf