* add letter bar with no links
* use lucene for search, add paged search results
* add search index version
* index library_name; rebuild index when folder is missing
* maintain index as local movies change
* fix tests
* maintain index as local shows change
* maintain index as plex movies change
* maintain index as plex shows change
* code cleanup
* add duplicate filter to search
* add links to letter bar
* code cleanup
* first pass at refresh-all-metadata by source
* add version to startup logs
* lock media source during refresh
* fix local media source "name" in collection editor
* optimize scanning so playouts only rebuild when necessary
* support more poster file types
* more scanning improvements; check for missing posters during scans
