a couple of library cache clearing methods and moves them to CacheHelperExtensions. Fixes #U4-1653 for 6.1 and updates ExamineEvents to
ensure that Examine re-indexes media on all of the correct events (including Trashed). Changes for Caching are being done to begin work with
CD-148
Updates Examine index configs to be simplified, don't need all of that config there!
Updates UmbracoExamine indexers to not initialize if the app/database is not ready.
Updates Examine event binders to not bind if the app/database is not ready.
Updates Examine events to use new 6.0+ events and removes binding entirely to the old api events (where we could)
Converts UmbracoContextService and UmbracoMediaService for UmbracoExamine to use the new data api's
to extract latest data. Currently had to hack a bit with a new class called LegacyLibrary because at the moment
we'll have a circular dependency with Umbraco.Web which needs to be fixed. Moves all Examine event management to
Umbraco.Web (again mainly because of circular dependencies, but makes sense to have it there). Fixes the ExamineEvents
to implement IApplicationEventHandler instead of IApplicationStartupHandler to ensure that all resolvers have been
initialized before attempting to initialize examine indexes. Updates Examine ILogService to use the LogHelper.
Adds some new ContentExtensions for IMedia since currently Examine needs xml structures, but have kept it internal.
