Add emin, zeh; Major updates to etr, vip; Minor to wgt, topn, ft

This is really a long overdue release.

• Document & install bu/emin

• etr gets a big update to do

  • its own looping poll when -m is given using a pretty fancy
    progress rate estimation based on recent adix histograms

  • take a kill command not signal number; -k15 -> -kkill

  • do nicer formatting & colorization of its messages which helps
    visibility if said are interleaved with monitored program output

• vip gets..

  • a bug fix for short inputs or cursoring past the end of any
    inputs & some doc tweaks.

  • new option --rev to NOT reverse input (double negative I know)

  • new option --quit to pass a string to echo on Ctrl-C and also a
    bug fix to use this when ENTER is pressed on filtered-to-empty

  • Ctrl-T now toggles case (in)sensitivity while TAB is now an alias
    for down arrow.

  • Cursoring up or down one-by-one now wraps around matched items,
    while PgDn/PgUp remain stopped by EOF & BOF.

  • Hook/plug-in/loadable module system for lazy/delayed test to show
    items. Deferred validation helps big sets of "maybe bad" entries
    with slow entry validation. The motivating use case is PWD history
    to cd into. There transiently unavailable dirs like USB drive/net
    mounts coexist with "live" dirs (& permanently gone temp dirs).
    AFAICT, though lazy loading is ancient wisdom, vip is the first
    terminal UI picker w/this ability built-in. See doc/vip.md.

  • (NOTE: Home-End seem to not register in emacs ansi-term|xterm,
    but I did not want to delay the release over that.)

• zeh added to manipulate Zsh Extended History. See zeh.md

• wgt sample exclusion file, topn can emit row slices, ft code
  matches docs for perm bits&grows --stat; Misc.code beautification.