Bundled Purging, hashed tags, varnish proxy instance name config

NOTE: Make sure you delete the section_purger folder from modules before you update to this version as the tags header module was merged into the purger module for the sake of consistency as well as (now) required dependency.
-SectionBundledPurger added - will bundle tag purges into one API call
-Cache tags are now hashed for shortening data and privacy/security
-The header for cache tags must now be Section-Cache-Tags
-Varnish proxy instance names are now configurable. Read more in readme
-Raw VCL expression invalidations are now their own type: raw. Resultingly, regex invalidations now follow convention.