Try to output editsection markers instead of rendered editsection links and defer...

Try to output editsection markers instead of rendered editsection links and defer the rendering to a point where the markup does not need to be stored in the cache.
Doing this allows skins to override doEditSectionLinks without poluting the parser cache or fragmenting the parser cache more.
As a side effect it eliminates the primary cause of user language based parser cache fragmentation.
Because this makes most old parser cache entries invalid $wgUseEditSectionTokens is provided so that large installations like Wikipedia can keep their old parser cache entries.