* packages/debbugs/debbugs-gnu.el (debbugs-gnu-search):
Call `completing-read' with `require-match'.
(debbugs-gnu-completion-table): New defvar.
(debbugs-gnu-send-control-message): Ask for version only for
"emacs" package. Use `debbugs-gnu-completion-table' for "merge",
"forcemerge" and "block".
(debbugs-gnu-bugs): Use `debbugs-gnu-completion-table'.
* packages/debbugs/debbugs.el (debbugs-newest-bugs): Use cache.
(debbugs-get-status): Fix typo.