Issue #1893400 follow-up by sun: REALLY fix autocomplete this time. :P
Revert "Issue #1893400 follow-up by sun: REALLY fix autocomplete this time. :P"

Wrong commit credit.

This reverts commit 922b0916aa641ad0cf8d0b4f3733e788f2a9bacd.
Issue #1893400 follow-up by nod_: REALLY fix autocomplete this time. :P
Issue #1722882 follow-up by Berdir: Fixed CacheDecorator does not clear used cache tags.
Issue #1893740 by Gábor Hojtsy: Remove repeated 'Block' UI text from block editing, fix title.