Queue new content that will be searched vs spawning threads

When files were added they are immediately indexed using a threaded approach. This could potentially add a lot of overhead to the system when copying content including duplicating sites. It would seem preferable to make this more synchronous where files are not indexed immediately but they are queued. Then the next time the indexing thread runs, typically a maximum of a minute the files will be processed from the queue and indexed. This increases the synchronicity of the indexing operations and reduces the overhead when new files are added or copied. The only negative impact is that users content is not searchable until the document is indexed typically less than a minute after adding it.