Better error on 'opam source non-existing'
Less verbose OCaml compilation
Override MAKEFLAGS, MAKELEVEL variables

in case opam is run from a Makefile. Closes #1617
Better handling of invalid package names
Pins: Don't ask for install after aborted edit of template
simpler intf for update_dev_package
Merge pull request #1665 from OCamlPro/a-few-fixes

Fixing a few recent UI issues