bug#4725: 23.1; doc of misearch-* commands (commands?)

[Juri Linkov <juri@jurta.org>]

> If the list variable is already populated, then use that value. This lets users
> populate the variable ahead of time and then still use these commands
> interactively.
>
> If the list variable is null, then just have a simple loop for users to enter a
> buffer/file name (e.g. with completion), and end with an empty string. IOW, foo
> RET bar RET RET to give ("foo" "bar").

`multi-isearch' was designed to be similar to `multi-occur'.
Currently we have a set of commands:

  isearch-forward
      search for a string in the current buffer

  isearch-forward-regexp
      search for a regexp in the current buffer

  occur
      search for a regexp in the current buffer

  multi-occur
      search for a regexp through multiple buffers
      where the user specifies the buffer names one by one

  multi-occur-in-matching-buffers
      search for a regexp through multiple buffers
      where the user specifies the buffers to search by a regexp

What is missing now and candidates to be implemented are
8 analogous commands:

  multi-isearch-buffers
      search for a string through multiple buffers
      where the user specifies the buffer names one by one

  multi-isearch-buffers-regexp
      search for a regexp through multiple buffers
      where the user specifies the buffer names one by one

  multi-isearch-buffers-matching
      search for a string through multiple buffers
      where the user specifies the buffers to search by a regexp

  multi-isearch-buffers-regexp-matching
      search for a regexp through multiple buffers
      where the user specifies the buffers to search by a regexp

  multi-isearch-files
      search for a string through multiple files
      where the user specifies the file names one by one

  multi-isearch-files-regexp
      search for a regexp through multiple files
      where the user specifies the file names one by one

  multi-isearch-files-matching
      search for a string through multiple files
      where the user specifies the files to search by a regexp

  multi-isearch-files-regexp-matching
      search for a regexp through multiple files
      where the user specifies the files to search by a regexp

-- 
Juri Linkov
http://www.jurta.org/emacs/