ayende/ravendb — pull request #1634 by myarichuk (2014-11-23 14:16:25+00:00)
Title: fix for Raven-DB 2911

* if index is marked in stats with IsInvalidIndex == true / its priority is Error/Disabled -> then dynamic query will not use it
* if index is marked with priority Abandoned/Idle -> then dynamic query will prefer to use another index, and use the Abandoned/Idle one only if active index is not found