Add well-formed package.el header and footer

[DarwinAwardWinner]

This will allow ido-speed-hack to be included in melpa.

As suggested in melpa/melpa#1868

[milkypostman]

@danskarda PING!

[Wilfred]

In an ideal world, these improvements would be upstreamed to Emacs core.

Anywyay, as far as I can see, the ido.el only has changes to ido-read-internal (setting ido-cache-cur-list and ido-cache-cur-list-reverse) and ido-set-matches. These could be simple advice, making ido-speed-hack.el self-contained.

[Wilfred]

Playing with this some more, it's not sufficient to advice ido-read-internal and ido-set-matches. There's also two other commits: one, two which make a huge difference. Without these, I don't see a speedup.

(I'm testing on larger ido datasets, like C-h f, which has a ~3 second delay without ido-speed-hack.)