TYPO3 Core

Problem:
function getTreeList() in class tslib_content can be some of the most expensive functions when rendering pages showing plugins that use huge pidlists.

Solution:
Backport the treelist caching from TYPO3 4.3 to TYPO3 4.2.6

I did some benchmarks with a worst case scenario: complete pagetree is used as pidlist (~1000 pages). All pages did show a plugin using this pidlist and rendered as User_int.
Don't laugh ;-) I saw this quite often on realworld servers.

In these tests caching of the treelist resulted in 3 times more pages rendered in the same time (+ 200%)

(issue imported from #M11317)