Performance improvements and various fixes

These commits do a number of things:
 * Improve performance via traditional means (suspending cache invalidation, etc.) and less traditional means (applying knowledge of WP API internals to reduce taxonomy and meta queries, etc.)
 * Use post_name instead of post_title when searching for existing items, as proposed by @otto42.
 * Skip @ignore'd items as well as duplicate hooks.
 * Use :: to delimit class methods.
 * Print the file name as context when processing files.