[keycloak-dev] Added 'keycloak-server.json' to configure server

Keycloak is now configured through keycloak-server.json (standalone/deployments/auth-server.war/WEB-INF/classes/META-INF/keycloak-server.json). This file let's you configure: * Model provider - including hostname/port/etc for Mongo * Audit provider - including hostname/port/etc for Mongo * Theme - default theme name and dir * Scheduled - interval to run scheduled tasks I've also added an SPI interface, which is used to detect and load SPI's. Currently the following SPI's are registered: * ModelSpi * AuditProviderSpi * AuditListenerSpi * AuthenticationSpi * IdentityManagerSpi * TimerSpi There's a few 'providers' that needs to still be updated, these are themes, import/export and social.