Auto merge of #6663 - trentmwillis:cache-opt-out, r=rwjblue
Auto merge of #6663 - trentmwillis:cache-opt-out, r=rwjblue

Add stats and logging for addon tree caching opt out

This will make it easier to identify addons that are opting out of tree caching. This won't catch addons that define their own `cacheKeyForTree` method, but we should assume that means those addons are handling caching on their own.

romulomachado/ember-cli,HeroicEric/ember-cli,buschtoens/ember-cli,ef4/ember-cli,ef4/ember-cli,akatov/ember-cli,fpauser/ember-cli,kanongil/ember-cli,rtablada/ember-cli,asakusuma/ember-cli,jrjohnson/ember-cli,twokul/ember-cli,kategengler/ember-cli,patocallaghan/ember-cli,cibernox/ember-cli,gfvcastro/ember-cli,raycohen/ember-cli,kriswill/ember-cli,kanongil/ember-cli,kriswill/ember-cli,calderas/ember-cli,fpauser/ember-cli,trentmwillis/ember-cli,pzuraq/ember-cli,rtablada/ember-cli,gfvcastro/ember-cli,jgwhite/ember-cli,mike-north/ember-cli,kellyselden/ember-cli,fpauser/ember-cli,trentmwillis/ember-cli,HeroicEric/ember-cli,asakusuma/ember-cli,patocallaghan/ember-cli,patocallaghan/ember-cli,kriswill/ember-cli,balinterdi/ember-cli,kanongil/ember-cli,sivakumar-kailasam/ember-cli,raycohen/ember-cli,seawatts/ember-cli,akatov/ember-cli,kriswill/ember-cli,twokul/ember-cli,pzuraq/ember-cli,elwayman02/ember-cli,twokul/ember-cli,mike-north/ember-cli,thoov/ember-cli,thoov/ember-cli,Turbo87/ember-cli,kellyselden/ember-cli,pzuraq/ember-cli,Turbo87/ember-cli,akatov/ember-cli,fpauser/ember-cli,ember-cli/ember-cli,calderas/ember-cli,ef4/ember-cli,balinterdi/ember-cli,rtablada/ember-cli,twokul/ember-cli,jgwhite/ember-cli,gfvcastro/ember-cli,thoov/ember-cli,patocallaghan/ember-cli,trentmwillis/ember-cli,cibernox/ember-cli,kanongil/ember-cli,buschtoens/ember-cli,mike-north/ember-cli,kategengler/ember-cli,HeroicEric/ember-cli,ember-cli/ember-cli,Turbo87/ember-cli,ef4/ember-cli,elwayman02/ember-cli,akatov/ember-cli,seawatts/ember-cli,romulomachado/ember-cli,sivakumar-kailasam/ember-cli,Turbo87/ember-cli,gfvcastro/ember-cli,mike-north/ember-cli,cibernox/ember-cli,trentmwillis/ember-cli,rtablada/ember-cli,thoov/ember-cli,pzuraq/ember-cli,romulomachado/ember-cli,jgwhite/ember-cli,jgwhite/ember-cli,sivakumar-kailasam/ember-cli,seawatts/ember-cli,kellyselden/ember-cli,cibernox/ember-cli,romulomachado/ember-cli,jrjohnson/ember-cli,calderas/ember-cli,ember-cli/ember-cli,calderas/ember-cli,HeroicEric/ember-cli,seawatts/ember-cli,sivakumar-kailasam/ember-cli,kellyselden/ember-cli