Raised version to 7.6.4

Merge pull request FriendsOfTYPO3#23 from FriendsOfTYPO3/develop

[BUGFIX] Fix issue: FriendsOfTYPO3#21 wizard in flexform does not work

[TASK] Raise version to 7.6.2

[TASK] Added license information

Change-Id: I61361b8f82faaac5dcb80519ff421cdbee5466c4