selfweight_diag_connection_impl
===============================

Connection for layers of the same representation.  The input to the target layer
is calculated as follows.  For each element, sum an excitatory component and an
inhibitory component.  The excitatory component is `excitation` multiplied by 
the corresponding value on the source.  The inhibitionory component is the 
product of a selfweighting value and a mismatch value.  The selfweighting value
is `extra_inhibition` times source value plus `inhibition`.  The mismatch value
is the sum of the absolute values of all non-corresponding values on the source.

	target_i=exc*source_i+(inh+extra_inh*source_i)*sum_j_not_i(abs(source_j))

Parameters
----------

	parameter		default_value
	inhibition		0
	extra_inhibition	0
	excitation		0