v1.0.0

• Buses can now be created without names and a name will be
  automatically assigned. Or use "name=..." to manually assign a name.
  Or just place a string in the list of arguments and that will be used.
• Footprint search can now process directories of footprints without the
  need for an fp-lib-table file.
• Part fields can now be accessed using attributes.
• Creating fields requires use of Part.fields[key] instead of Part.key.
• Added context manager for Circuit object so Parts/Nets can be joined
  using a with... statement.
• Adding/removing Parts to/from a Circuit can now be done using += and -=.
• Tags can be added to Parts and Circuits for hierarchical naming.
• Part values can now be assigned arbitrary objects including units from either PySpice or Pint.
• Multi-function pin names can now be split into a collection of shorter aliases,
  thus reducing the need to access pins using regexes.
• Schematics can now be automatically using the KiCad symbol graphics for the parts.
• The library interface now handles the Skywater 130 SPICE libraries.