Build with -warn-error -a.
Ensure proper -I$(ocamlc -where) option is used by omake's dep scanning.
Needed so that the build does not fail if there's no system-wide OCaml
installed (e.g., when installed with ocamlbrew).
Bump version to 1.0.2.
Build and install .cmxs if ocamlopt supports native dynlink.
Use system-wide leveldb lib, greatly simplifying build.
Revert "Update makefile to opam.0.4"
This reverts commit 8e2315e.