YAML: Recognize non-specific tag `!`
YAML: Recognize non-specific tag `!`

Before this change Pygments would incorrectly mark the non-specific tag
as error token.

pygments/pygments,dscorbett/pygments,dscorbett/pygments,dscorbett/pygments,pygments/pygments,dscorbett/pygments,dscorbett/pygments,pygments/pygments,dscorbett/pygments,dscorbett/pygments,pygments/pygments,dscorbett/pygments,dscorbett/pygments,pygments/pygments,pygments/pygments,dscorbett/pygments,pygments/pygments,pygments/pygments,dscorbett/pygments,pygments/pygments,pygments/pygments,pygments/pygments,dscorbett/pygments,pygments/pygments,pygments/pygments,pygments/pygments,dscorbett/pygments,pygments/pygments,dscorbett/pygments,dscorbett/pygments,pygments/pygments,dscorbett/pygments,dscorbett/pygments,pygments/pygments,dscorbett/pygments,pygments/pygments