Allow svnlog2ul.sh to run on the current working copy

And from the root directory instead of having to cd to util/svnlog2ul
Original author: John Ralls <jralls@ceridwen.us>

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash-docs/trunk@22984 57a11ea4-9604-0410-9ed3-97b8803252fd
Add script to generate a list of changes in html format between two revisions based on git log

This is the equivalent of svnlog2ul.sh which does the same from svn log

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash-docs/trunk@22985 57a11ea4-9604-0410-9ed3-97b8803252fd