Issue #1786490 by Berdir, amateescu, damiankloip, Wim Leers, dawehner: Add caching to the state system.
Revert "Issue #1786490 by Berdir, amateescu, damiankloip, dawehner: Add caching to the state system." This reverts commit 8ec847cc.
Issue #1798738 by alexpott, mtift, tayzlor, ianmthomasuk, Albert Volkman, heyrocker, cam8001: Move css_js_query_string() to state system.
Issue #352951 by Wim Leers, mfer, mcjim, larowlan, RobLoach, sdboyer, Owen Barton, JohnAlbin: Make JS & CSS Preprocessing Pluggable.