Add require-checksums install option
Merge pull request #1497 from anemator/checksum

Add require-checksums install option
Release script: add support for ocaml-github
Add 'opam source'

Want to patch an existing package ? `opam source --dev --pin <package>` and start hacking.
Don't wipe non-empty directories that seem to remain after uninstall

rather print a warning. By 'seem to remain' I mean eg. 'lib/<pkgname>' when <pkgname> was just removed
Remove the unused 'build-dep' package flag

A better way to handle build-packages is being discussed
Merge pull request #1500 from OCamlPro/cleanup-and-source

Add `opam source`; fix uninstall ; some cleanup
Add checks for external dependencies at init (and some color)

Closes ##499
Merge pull request #1501 from OCamlPro/checks-at-init

Add checks for external dependencies at init (and some color)
Add 'opam repository set-url'

Closes #1288
Display a note after pinning operations when the action is aborted
Merge pull request #1503 from OCamlPro/pin-no-act

Display a note after pinning operations when the action is aborted
Merge pull request #1502 from OCamlPro/set-url

Add 'opam repository set-url'
Add git version info to 'opam show'
Merge pull request #1504 from OCamlPro/show-git-version

Add git version info to 'opam show'
Don't remove build dir after failed install

Closes #1348, thanks for reporting
Merge pull request #1506 from OCamlPro/fail-build

Don't remove build dir after failed install
Add an 'install' field
Re-enabled read locks

The part that needed fixing for the tests was that some 'switch' commands
were keeping a global lock for package installs. They now properly relax to
a switch lock once the global operations are done, before getting to package
installs
Merge pull request #1507 from OCamlPro/read-locks

Re-enabled read locks