Updated Insteon state definition for new Insteon object model

Moved responsibility for Insteon states out of http_server.pl and
into the Insteon objects themselves. (i.e. Insteon::DimmableLight)
The existing code was not working with the new object model.  This
is an additional fix for Issue #212.

Open Issue:  http_server.pl->button_action() probably needs to
be modified so Insteon lights dim/brighten correctly.  It
doesn't look like is_dimable() was ever implemented for any MH
object.
Modified insteon_menu_states in mh.ini to match new behavior model

peloy implemented a new behavior model for the web interface when
changing Insteon dimmable devices.  This model steps up/down then
states array with each web button press.  The order and content of
the states array is importand with this behavior model.