d/rules: replace override_dh_auto_install with d/sfnt2woff-zopfli.install. Provide bin:woff-tools as a transitional package, with compat links in sfnt2woff-zopfli. Rebase patches from src:woff-tools. Fix segfault due to #785795. Link to system zopfli inst

...ead of building embedded copy

The salvage team would like to replace the old src:woff-tools package with a maintained fork, which sfnt2woff-zopfli is. This MR should implement this transition transparently to users, and will allow RM src:woff-tools.

The transition will be complete in forky by applying the TODOs in d/control and dropping the dh_gencontrol override.

Files-Excludeding zopfli would also be a good idea IMO, but that'd mean a repack which I can't express in an MR.