Connector pins (e.g. J12-1 through J12-53) were imported as
separate single-pin symbols instead of units of one shared
symbol. Add BuildMultiUnitConnectorSymbol which creates a
multi-unit LIB_SYMBOL where each unit has the connector decal
graphics and one pin with the correct number.
Multi-gate parts like TL082 (U1-A, U1-B) appeared as separate
symbols because AddHierarchicalReference was called with the
unsuffixed reference "U1-A" instead of the stripped "U1".
Also move the connector SetRef call to after ApplyPartAttributes,
which only strips alphabetic gate suffixes and would otherwise
override the base reference back to "J12-1".
Seth Hillbrand
a58e14178e