This changes ve.dm.LinkAnnotation to be a generic annotation for <a>
tags, and adds ve.dm.MWInternalLinkAnnotation and
ve.dm.MWExternalLinkAnnotation as MW-specific subclasses. This nicely
splits out the MW-specific parts in LinkAnnotation, and ideally we'd
also move these files somewhere else to reflect their MW-specificity,
but I haven't gotten to that yet.
Similarly, ve.dm.TextStyleAnnotation is now a generic base class for
simple tag-only-no-metadata annotations, and it has 11 subclasses, one
for each tag we support. This is quite a bit more verbose than the
previous code, but I think it's cleaner and more flexible. I considered
writing a function that would generate a TextStyleAnnotation subclass,
then calling that 11 times, but that's not possible if we want to keep
named functions for the constructors.
Change-Id: Ifba10153eef40280e44025dd72d4e9d9f33b0632
