(mbx_write) [MAIL_USE_POP]: Disable the code which quotes with a

(mbx_write) [MAIL_USE_POP]: Disable the code which quotes with a
'>' any lines starting with "From " read from the POP server, but
leave the code in place, wrapped in #ifdef
MOVEMAIL_QUOTE_POP_FROM_LINES, in case we have to restore it later
because it turns out that something is depending on it.  Change
suggested by Paul Eggert <eggert@twinsun.com>.
Convert the character \037 (^_) at the beginning of a line into
the character '^' followed by the character '_', because otherwise
Emacs can't parse the resulting file as a valid BABYL file.
Change suggested by Paul Eggert <eggert@twinsun.com>.