add base64 module to .merlin
Base64 -> B64 rename
constrain base64 to 2.0.0 and above
Merge pull request #222 from rgrinberg/base64_fix

Base64 fix
Merge branch 'master' of github.com:mirage/ocaml-cohttp

Conflicts:
	opam
sync CHANGES
Travis: simplify and just test on OPAM 1.2 now