[9fans] long paths in acme tags

[Bakul Shah <bakul@bitblocks.com>]

If you are editing multiple file within the same directory
with a very long path, the long dir paths is what takes up
most of the tag. One idea (borrowed from zsh) is to assign a
long path to a variable and then just show the variable
instead. Thus for example, given long paths like these:

    /a/very/very/very/very/very/very/very/very/very/long/path/to/a/file1
    /a/very/very/very/very/very/very/very/very/very/long/path/to/a/file2

If one can define a variable in acme
    foo=/a/very/very/very/very/very/very/very/very/very/long/path/to/a

& if the acme tags show
    $foo/file1
    $foo/file2
it would be much nicer.

Has anyone considered doing this or is there a better idea?  I
suppose on plan9 one can use bind for this but on p9p things
get considerably clunkier (9p, fuse...) when a variable can do
the job more simply.