Make it go faster!

Started on optimization... initially, just rewrite recv-message &
friends to use '(array (unsigned-byte 8)) instead of a list to hold the
received content. So far, this looks good (speedups from 3 to 12 times
have been observed.)
Cleanup

Removed dead/commented-out code.
Loop mistake: use "... downfrom ..." and not "... by -1 ..."
Discard "controls" content after processing.
Revert: looks like we need to unescape after all

(This may require a closer analysis.)
No, we don't need to use unescape-string...

... the only place we need it, is when deconstructing a dn, and that
should be done in client code, instead.
Silently ignore size limit exceeded from server
Merge branch 'gofaster' of https://github.com/rwiker/trivial-ldap into gofaster