see parent issue for context.
- CoreContainer should keep a record of failures related to core initialization, keyed off of the core name
- failures should be recorded for both solr.xml initialzation, as well as explicit CREATE/RELOAD requests that fail
- record of failures should be tracked indefinitely until some valid core begins using that name
- ie: actions which register a SolrCore with a name (RELOAD, CREATE, SWAP, ALIAS) should "reset" any existing failures associated with that name
- failures should be available to clients via CoreAdminHandler STATUS actions