extraction: Fixed a problem causing long extraction times, at
least some of which had to do with a poor string hash function
implementation. Fixed a huge problem in ext2spice, where the
node merge function was particularly poorly implemented, causing
exponentially increasing processing times with layout size.
Corrected a minor issue with ext2spice where arguments were
improperly specified, causing unnecessary error messages to be
issued. Fixed an error in the "load -dereference" command option,
which again caused unnecessary error messages to be issued.
Changed .gitignore to ignore Depend files, which are now regenerated
on every build.
8.2.74. Top-level port names are now flagged independently of
any subcircuit port, so they are easier to identify when determining
naming precedence for the net. This makes the code cleaner and
removes the problems arising from non-top-level ports and global
names overriding the subcircuit port names.
Tim Edwards