[ocaml-platform] [ANN] OPAM 1.1.0 Release Candidate

[Louis Gesbert]

OPAM 1.1.0 is ready, and we are shipping a release candidate for packagers and 
all interested to try it out.

This version features several bug-fixes over the September beta release, and 
quite a few stability and usability improvements. Thanks to all beta-testers 
who have taken the time to file reports, and helped a lot tackling the 
remaining issues.

# OPAM

OPAM is a source-based package manager for OCaml. It supports multiple
simultaneous compiler installations, flexible package constraints, and
a Git-friendly development workflow. OPAM is edited and
maintained by OCamlPro, with continuous support from OCamlLabs and the
community at large (including its main industrial users such as
Jane-Street and Citrix).

# Repository change to opam.ocaml.org

This release is synchronized with the migration of the main repository from 
ocamlpro.com to ocaml.org. A redirection has been put in place, so that all 
up-to-date installation of OPAM should be redirected seamlessly.
OPAM 1.0 instances will stay on the old repository, so that they won't be 
broken by incompatible package updates.

We are very happy to see the impressive amount of contributions to the OPAM 
repository, and this change, together with the licensing of all metadata under 
CC0 (almost pubic domain), guarantees that these efforts belong to the 
community.

# If you are upgrading from 1.0

The internal state will need to be upgraded at the first run of OPAM 1.1.0.
THIS PROCESS CANNOT BE REVERTED. We have tried hard to make it fault-
resistant, but failures might happen. In case you have precious data in your 
~/.opam folder, it is advised to backup that folder before you upgrade to 
1.1.0.

# Installing

Using the binary installer:
- download and run http://www.ocamlpro.com/pub/opam_installer.sh
 
You can also get the new version either from Anil's unstable PPA:
    add-apt-repository ppa:avsm/ppa-testing
    apt-get update
    sudo apt-get install opam
 
or build it from sources at :
- http://www.ocamlpro.com/pub/opam-full-1.1.0.tar.gz
- https://github.com/OCamlPro/opam/releases/tag/1.1.0-RC

# Changes

Too many to list here, see
https://raw.github.com/OCamlPro/opam/1.1.0-RC/CHANGES

For packagers, some new fields have appeared in the OPAM description format:
- `depexts` provides facilities for dealing with system (non ocaml) 
  dependencies
- `messages`, `post-messages` can be used to notify the user or help her 
  troobleshoot at package installation.
- `available` supersedes `ocaml-version` and `os` constraints, and can contain
  more expressive formulas


Enjoy !

Louis / OCamlPro & all the OPAM team