Added comments.
Decouple more controllers from config reader.
Inject configuration.
Created mechanism for reloading configuration through plugin manager.
Note: this will create some inefficiency until \VuFind\Config\Reader is factored out of code; in some cases, configurations will load twice.  Should be sorted out soon.
Inject configurations into cache manager.
Inject configuration into sitemap generator.
Avoid potentially inappropriate direct data access.
Eliminate unnecessary config loading.
Added missing comments.
Moved extractComments() from Reader to Upgrade class since it is only used in one place.
This might deserve its own class if it ever needs to be reused in the future.
Decoupled from config\reader.
More configuration decoupling.