[TYPO3-core] FYI: #13327: Update ExtJS to version 3.1

[Benjamin Mack]

Hey,

just a quick info from my side: I know that feeditadvanced is using Ext 
core. Works great. In addition I see no harm in updating Ext Core from 
3.0RC2 to 3.0, there should be no breaking changes at all.

Thus, Steffen: Go ahead with FYI-ing the update of Ext Core in trunk, 
and probably for 4.3.x as well.

And no: we should not use our own copy of Ext Core in our extensions. ;-).

And not so by the way: Steffen, thank you very much for keeping an eye 
on these updates! Great work!

All the best,
Benni.