Previous, reverted attempt: da9b6fffbd.
This attempt also includes 6037fefbe0,
and fixes minor conflicts with other changes.
* In normal images, parse relative 'href' attributes instead of
expanding them to absolute. This resolves Parsoid generating
|link= options for copy-pasted images (T193253).
Keep them in the underscore-form to avoid causing dirty diffs like
T237040 again. Unlike in the previous attempt, we don't need to be
super-careful about the 'resource' attribute, thanks to the Parsoid
changes in T108504.
* In gallery images stuff, prefix the 'resource' attribute with './',
same as normal images do. This causes no functional changes, but it
makes updating tests easier, and the consistency is probably good.
* Update test examples to also prefix 'resource' and relative 'href'
attributes with './', like the real Parsoid does.
Bug: T193253
Change-Id: I91131728a87c9406bf069d46d3c94c9a8905a003
91291d3e98