Issue #2233787 by alexpott, xjm | tim.plunkett: Move default configuration into extension/config/install to clarify its purpose.

Issue #2080823 by alexpott, swentel, Wim Leers: Create API to discover content or config entities' soft dependencies and use this to present a confirm form on module uninstall.

Issue #2167623 by danilenko_dn, sidharthap, Nitesh Sethia, krishnan.n, aitiba, alexpott, ashwinikumar, Barrett, damiankloip, deepakaryan1988, foxtrotcharlie, ianthomas_uk, neetu morwani, nonsie, piyuesh23, Sharique, sivaji, sushantpaste, swentel, vijaycs85, YesCT: Add test for all default configuration to ensure schema exists and is correct.

Issue #1605290 by amateescu, msonnabaum, Caseledde, damiankloip, beejeebus, catch, Berdir, Wim Leers: Enable entity render caching with cache tag support.