Modules have to return true;
Need a modern wing to pull this off.
Need WING_CONFIG, too for Wing->db to work.
Add prepare_install, so that we don't rewrite the install files every time we install.
Rough in code for handling one tenant.
Fix a variable name.
DBIx::Class::DeploymentHandler based installs for Wing tenant sites.
Add handling for tenants.  So far all that has been tested is prepare_install and install.
Unify setting up the tenant libraries, so that --tenant and --all_tenants both have libraries and modules handled the same way.  Add the --all_tenants switch.
Use modules before accessing them.  Upgrade code for all tenants.
Add multi-tenant downgrade code, fix both upgrade and downgrade code.
Merge branch 'saltless', bringing in multi-tenant database support.

Conflicts:
	bin/wing_db.pl