Add text-align setter to the Style class
Add text-align setter to the Style class

Getter is excluded under the assumption that the user is hooking into the generic getter/setter, which will evaluate to the correct value if no value is set. Per the spec: a nameless value that acts as 'left' if 'direction' is 'ltr', 'right' if 'direction' is 'rtl'.

dompdf/dompdf,dompdf/dompdf,BrunoDeBarros/dompdf,BrunoDeBarros/dompdf