i/if_ignore cleanup (#377)

* does not have an i_ignore function, don't mention it in the docs

* these interfaces don't even exist on oneaccess

remove i_ignore, mark tests as complete now

* don't see a reason for a function, so remove it:

sub i_ignore {return;}

lib/SNMP/Info/Layer2/Baystack.pm

@@ -552,10 +552,6 @@ Returns reference to the map between IID and physical Port.
 
   The physical port name is returned as slot.port.
 
-=item $baystack->i_ignore()
-
-Returns reference to hash of IIDs to ignore.
-
 =item $baystack->i_mac()
 
 Returns the C<ifPhysAddress> table entries.