overhaul was to introduce the concept of a "connection point"
between two cells to the ".ext" file format so that it becomes
possible to do proper hierarchical R-C extraction. Previously
this information was not kept in the .ext file, making it
impossible for "extresist" to know what sub-net of a net connects
up or down the hierarchy. However, additional changes were made
to the extresist code (in the resis/ directory) to add the
handling of connections up and down the hierarchy, and to make
the code a lot clearer and fix ambiguous variable and subroutine
names.