Config.init() derives the location of config.json from window.location,
which only makes sense while Element Call owns the page. When it is
embedded in a host application the host owns the configuration, so add
Config.initWith() to accept it directly.
Share the defaulting and validation between both paths via resolveConfig(),
so that an injected config behaves identically to a fetched one, and mark
initialization as complete so that the init() calls already on the startup
path resolve immediately instead of fetching over the top of it.
initDefault() becomes initWith({}), which also stops it handing out a
shallow copy of DEFAULT_CONFIG whose nested objects were shared with the
module-level default.
Valere
fkwpandJohannes Marbach