Major overhaul of caching system
Merge branch 'master' of github.com:WoltLab/com.woltlab.wcf.tagging

Conflicts:
	files/lib/system/cache/builder/TagCloudCacheBuilder.class.php
	files/lib/system/cache/builder/TypedTagCloudCacheBuilder.class.php
	files/lib/system/tagging/TagCloud.class.php