Add micro benchmarks
Avoid allocating when reading int64 on ocaml 4.00
Bump version to 0.3
Update README.md
Remove runtime dependency on optcomp (Fixes #1)
Bump version to 0.4
Add travis files
return code in tests
Avoid problems with integers outside of the range [0; 255] with set_int8.

Adds also a few tests to verify the behavior of String.set and Bigarray.Array1.set don't change