Merge remote-tracking branch 'upstream/master'

Update LICENSE [ci skip]

Bump api version to 7.0

Allow single card as forced parameter in synchro/xyz/link summonable

Bump version

Debug.AddCard, properly add card as overlayed material even for cards…

… in spell/trap zone, updated MSG_RELOAD_FIELD accordingly

Attempt to fix gcc compilation

Bump core version

Bump api version to 4.2

Bump version to 4.1