Substitute the OPAM version in the META file
Correct the findlib package to "opam-lib"
Improve upgrade message
git backend: get upstream checked out commit/branch rather than master
Automatically set pinning kind to version-control if detected
Travis: Add OSX CI to the test matrix
Travis: Install system OPAM too
Show more accurate `opam config setup` instructions.

The backtick is confusing since it's actually necessary
to specify with `opam config env`
Merge pull request #1558 from avsm/fix-opam-config-note

Show more accurate `opam config setup` instructions.
Merge pull request #1556 from OCamlPro/pinning-vc

Improve pinning version control
Merge pull request #1554 from Chris00/master

Fix META.in
Merge pull request #1557 from avsm/osx-ci

Travis: Add OSX CI to the test matrix
Consistently advertise opam-lib package in opam and ocamlfind
Travis: install opam with apt-get in test mode
Safeguard: fail on empty solution unless --no-base-packages
Merge pull request #1560 from OCamlPro/fix-install-travis-safeguard

Fix opam-lib package name at 'make libinstall', new travis tests; safeguard on removing everything.
Configure solver prefs in ~/.opam/config, detect newer aspcud
Fixed bug with git backend

fetch explicitely the remote HEAD when no branch is specified
(I was under the misconception that FETCH_HEAD was the remote HEAD,
while it is just the first alphabetical element of .git/FETCH_HEADS,
which could get you on a random branch. ugh.)
Fixed patching error messages and '--fake' with patches
Strengthen handling of undefined variables a bit