feat: add support for ! history and readline command in roundup-admin Ad support to change input mode emacs/vi using new 'readline' roundup-admin command. Also bind keys to command/input strings, List numbered history and allow rerunning a command with !<number> or allow user to edit it using !<number>:p. admin_guide.txt: Added docs. admin.py: add functionality. Reconcile import commands to standard. Replace IOError with FileNotFoundError no that we have removed python 2.7 support. Add support for identifying backend used to supply line editing/history functions. Add support for saving commands sent on stdin to history to allow preloading of history. test_admin.py: Test code. Can't test mode changes as lack of pty when driving command line turns off line editing in readline/pyreadline3. Similarly can't test key bindings/settings. Some refactoring of test conditions that had to change because of additional output reporting backend library.

@import url(style.css);

body { padding: 0;}
body > .header,
body > .footer
{
  margin: 0;
}
body .content { width: auto;}
.header h1 { font-size: 110%; }

table.classhelp th
{
  border-top: 1px solid #afafaf;
  border-bottom: 1px solid #afafaf;
  empty-cells: show;
  text-align: left;
  vertical-align: middle;
  white-space: nowrap;
}

table.classhelp td
{
  border-bottom: 1px solid #efefef;
  empty-cells: show;
  text-align: left;
  vertical-align: middle;
  white-space: nowrap;
}