TO_DO list for version 1.4
------------------------------

 1) Expand upon the details of format-to-format translation, (especially
    ntk and ext formats, SPICE format writing, and sim format reading).
 2) Add a "property" command to add/remove properties to check, and change
    the slop values (done).
 3) Add a "subcircuit" command to mimic a SPICE ".SUBCKT ... .ENDS" card.
 4) Parallel (transistors and capacitors) and serial (resistors)
    device merging.
 5) Translate automorphisms to pin permutations when doing "equate pins"

Possible useful additions (not critical)
----------------------

 1) Add new output style allowing netlists to be described by Tcl scripts
    (similar to the C-Code format, but does not require compiling).
 2) Add automatic file format guessing from file extension for "write" command
 3) Add Tk GUI to match (and improve upon!) the original X11 GUI.
 4) Incorporate into Tcl-based xcircuit
 5) Extend 2-terminal device handling (namely R and C) to more formats
    (where appropriate).
 6) Generate feedback in the form of a .mag file to facilitate interactive
    netlist comparison in conjunction with magic.  This may be an error
    file, but it may also make use of magic 7.2's "element" command to
    build rat's nests or outline areas of interest or anything else that
    might be helpful to interactive comparison.
 7) Improve upon the readability of the netlist comparator output.
    In particular, pinpoint situations in which an error does not show
    up in an obvious way in either the element or node lists.
 8) Handle the hierarchy of ".ext" files automatically.
 9) Retain position information from ".ext" files for the purpose of writing
    feedback information into magic and for matching devices in the element
    list to their counterparts in the original layout [note---done for .sim
    format, which contains position information.  Usefulness of improving
    the .ext parsing is questionable.  Ditto for item 8].
10) Add transmission lines to SPICE format reading


