document depCache idea in builder API
document depCache idea in builder API

jspm/jspm-cli,apiv/jspm-cli,jackfranklin/jspm-cli,apiv/jspm-cli,hmps/jspm-cli,jspm/jspm-cli,hmps/jspm-cli,hmps/jspm-cli,jackfranklin/jspm-cli,jackfranklin/jspm-cli,apiv/jspm-cli,jspm/jspm-cli