convert/svn: delegate to svn bindings if HTTP probe fails
convert extension tries to guess the remote repository type with HTTP probes.
Unfortunately, it does not handle authentication or HTTPS handshakes, so regular
svn repositories may be excluded. Instead, when a non-404 error is retrieved,
we keep trying with the svn bindings. The drawback is missing svn bindings will
make the conversion to fail even for non-svn targets. This can be avoided with
--source.
mdiff: fix diff -b/B/w on mixed whitespace hunks (
issue127)
Previous code was computing hunks then checking if these hunks could be ignored
when taking whitespace/blank-lines options in accounts. This approach is simple
but fails with hunks containing both whitespace and non-whitespace changes, the
whole hunk is emitted while it can be mostly made of whitespace. The new
version normalize the whitespaces before hunk generation, and test for
blank-lines afterwards.