FIX: Groups should be able to have titles longer than 50 characters (Fixes: open/5611)
Merge pull request #1334 from wilr/5611

FIX: Groups should be able to have titles longer than 50 characters
Fixed static config access in Currency and i18n (fixes #8341)
Fixed static config in BBCodeParser (fixes #8340)
FIX Clone Config_LRU incl. objects in array

Caused key confusions when using Config::nest()/unnest()
Clarified 3.1 upgrading docs
Merge pull request #1335 from chillu/pulls/config-clone-nest

FIX Clone Config_LRU incl. objects in array
Fixed _config.php references and usage in docs
Config docs improvement: @config and LSB mentions

Also moved some less important "notes" further down the page.
The doc is still written too much like a technical spec, we need
something that's more accessible to beginners.
Merge remote-tracking branch 'origin/3.1'