Add google-drive-ocamlfuse 0.5.5

ATM, if you do not put it in a local dir `opam/files`, then `oasis2opam` will not pick it up.  I'll try to update `oasis2opam` for that.

@samoht Are a local `opam/files/xxx.install` and `xxx.install` deemed equivalent in all situations or is the short version preferred?  What happens if both are present?  (For people using oasis, keeping things in the `opam` dir may make more sense to isolate generated files.)