Clean up LDAP login

Validate that username and password were entered.  Handle errors more
cleanly and with nice user messages.  Add translation for connection
issue.
Merge pull request #685 from jrjohnson/645-ldappass

Clean up LDAP login
Backport Vagrant Updates from I3

Update OS, and use Librarian, hiera, and better puppet manifests to
organize our vagrant build.  Mirrors the changes made in Ilios 3
without the symphony stuff.
Merge pull request #691 from jrjohnson/bettervagrant

Backport Vagrant Updates from I3
Merge branch 'master' of github.com:ilios/ilios into 666_objective_mesh_total_bugfix