add ivy package

with depext to install the ivy-c this ocaml package wraps from source on linux
Merge pull request #1867 from avsm/camlunity-master

Lwt + 0install fixes
ivy: add some more depexts to build ivy-c for debian/ubuntu
oasis2opam: add constraint oasis < "0.4.2"

Fixes https://github.com/ocaml/opam-repository/pull/1865#issuecomment-39663752
Merge pull request #1692 from flixr/ivy-ocaml.1.2.2

add ivy-ocaml package
Sync latest compiler pull requests
use gnu make in opium
Merge pull request #1870 from bactrian/sync-prs-1396802363

Sync OCaml compiler PRs
Merge pull request #1869 from Chris00/master

oasis2opam: add constraint oasis < "0.4.2"
Merge pull request #1866 from rgrinberg/master

opium 0.6.2
updated URL and MD5 for v0.0.5
core 111.08.00
Add piqi-0.7.0 and piqilib-0.6.6
Merge pull request #1872 from alavrik/master

Add piqi-0.7.0 and piqilib-0.6.6
Merge pull request #1871 from UnixJunkie/obuild_0.0.5

updated URL and MD5 for v0.0.5
Sync latest compiler pull requests
Merge pull request #1873 from bactrian/sync-prs-1396911601

Sync OCaml compiler PRs
Merge pull request #1852 from janestreet/core-111.08.00

Core 111.08.00
opium 0.6.3
Add gdal 0.1.1