Fix Lazy Package Loads

[matthewphsmith]

Proposed fix to issue: #15

• Ensure that when a package of a lazy-loaded module is loaded, the
  lazy-loaded module remains an attribute of the newly loaded package.
• Ensure that when two lazy-loaded modules exist in the same lazy package,
  the second (and all subsequent) lazy-modules are also added to the lazy
  package's list of lazy sub-modules.