Add code to generate ChangeLog from git

This code will determine the repo type (git or svn) and use the
appropriate command to generate the ChangeLog file accordingly.

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@22982 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/trunk@22983 57a11ea4-9604-0410-9ed3-97b8803252fd