fix opam pin with local opam file
fix exists_dir
fix opam pin when no version and name
Fixed version-pinned packages installation and removal
Fixed tests when aspcud is used
fix autoremove when aspcud is installed
Merge pull request #823 from AltGr/fix-aspcud-and-pin

Fix aspcud and pin
Do not delete compiler descriptions of still installed compilers at update
Only complain about missing metadata for packages in the current switch
Accepting to version-pin uninstalled packages
Reclassing errors about removed stale files as warnings
Fix #818
Fix #819

Use 'opam update -u' to chain 'opam update' and 'opam upgrade --yes'
(Partially) update CHANGES
Fix #821

Use light blue instead of blue to see somthing on dark background
Fix #781 and #808

As we are not caching/building the +opam.tar.gz anymore, the checksum checking code was not used anymore. Fix that, and use a cache of upstream packages as well.
Merge branch 'master' of github.com:OCamlPro/opam

Conflicts:
	src/client/opamArg.ml
Merge pull request #831 from samoht/master

Various fixes
Fixed warnings about missing metadata on pinned packages
The overlays are now used in state.opams which should be more consistent, and
warnings about metadata missing in a repo can be avoided with an overlay

AMEND (comments on #825): don't store overlays in the state cache (that could get inconsistent).
Instead, honor overlays everywhere ('available', universe...)
Remove the dev-pkg directory at uninstall, avoiding warning on next command
Atm we re-download anyway (really need to cache upstream files), so this seems harmless

AMEND (comments on #825): remove dev archives only when package isn't installed in any switch anymore