ocaml-camomile: Update to 0.8.5

Ubuntu insists on installing its v0.8.4 package ahead of
our v0.8.3 one.   0.8.5 is the latest version, so if we
update to that we will trump Ubuntu's version.

Signed-off-by: Euan Harris <euan.harris@citrix.com>
Merge pull request #269 from euanh/build-improvements

ocaml-camomile: Update to 0.8.5