modules.py: reload now returns boolean success, fix a bug with unloading modules.

Previously modules would not properly have their keys deleted,
 this has been fixed.

reload() now returns a boolean, if it is false either the unloading or loading
 failed. If it is true both load() and unload() returned True.
basics.py: Adds a lot of module-related commands.

The following commands were added:
  loadmodule (lmod),
  unloadmodule (umod),
  reloadmodule (rmod),
  availablemodules (amod)

The following alias was added:
  'mod' is now aliased to 'loadedmodules'.