Log Message:
Updated package to latest version, 1.2.2. Changes include:

1.2.2
* Fixed wrong locks being taken during `switch reinstall` (#2051)
* Fixed `config report` that wasn't displaying the external solver (#2059)
* Follow glibc standard on detecting an UTF8 locale (#2065)
* Fixed issues with fish shell init scripts (#2063)
* Restored printing of commands with `--verbose` and `--dry-run`
* More concise printing of conflicts, with accurate version numbers
* Small improvements to the causes of actions
* Fixed issue causing the state cache not to be used on some OSes (OSX) (#2077)
* Added numbers to lint checks, and some new checks
* Restored the handling of a simple path to an `aspcud`-compatible executable
  in variable OPAMEXTERNALSOLVER (#2085)
* Added package universe output to new PEF format for diagnostics
* Prioritise newer versions even when the latest can't be installed (#2109)
* Automatically install plugins on `opam plugin-name` (#2092)
* Fixed a fd leak on solver calls (#2134)
* Accept opam files with errors when no debug or strict options are set, for
  easier format updates
* Add `opam list --resolve` to get dependencies as a consistent set of packages
* Provide the expected checksum to download commands
* Changed return code of `opam list` when no patterns are supplied and the list
  is empty

1.2.1
* Non-system compiler definitions without source are now allowed
* Better handling of compiler "base" packages allows to move build \ 
instructions
  from compiler definitions to packages
* Rewritten action resolution mechanism to be based on atomic actions.
  Actions are not aborted anymore on first failure when there is no
  inter-dependency
* Rewritten parallel command execution engine
* Better display of actions, lots of improved messages
* `opam upgrade pkg` now fails if no new version of `pkg` can be installed
* fixed shell configuration for various shells
* Updated Dose dependency to 3.3
* Fixed behaviour of `opam switch` and related commands when a switch
  is locally set in a shell (through `OPAMSWITCH`)
* Better behaviour on failed `opam switch`
* New pinning mode: when pinning using version-control on a local path and
  without a branch specified, use current file tree, but limited to
  version-tracked files
* Faster and cleaner handling of downloads
* Now compiles with --safe-string on OCaml 4.02, better compatibility handling
* `opam unpin` now accepts multiple arguments
* `opam pin add <pkg>.<version> <target>` is now allowed to specify
  the advertised version
* Fixed bug leading to a bad `CAML_LD_LIBRARY_PATH` when switching from system
* Better `opam lint`, reporting warnings and errors, including format errors
* `opam config setup` now takes `--shell=` instead of `--sh`, `--csh`, `--fish`,
  `--zsh`
* Provisional feature: dependency flag `dev` is accepted (but does nothing)
* Provisional feature: field `features` in opam files implemented (beta), not
  for use in production
* Better definition of the `filter` language within opam files: propagates
  undefined values, bool-to-string converter syntax
* Provisional feature: `verbose` may be specified in package flags
* OPAM git-like plugins (commands of the form opam-xxx) are now searched in the
  correct OPAM path
* ~/.opam/config doesn't refer to OPAM's patch-version anymore, to allow
  downgrading
* Recognise <name>.opam files and directories when pinning a package to source
* Cleaned up debug and verbose messages, allow more control (`-v` can now be
  repeated)
* Pinning URL can now be explicit in the form `VC+URL`, e.g. `git+ssh://`,
  `hg+https://`...
* New flexible way to specify download and solver commands in `~/.opam/config`
  or in variables `OPAMFETCH` and `OPAMEXTERNALSOLVER`
* Lots of bug-fixes