disallow '\n' and '\r' in tag names
add a test for disallowed characters in tag names
%%% should show a removed and b addedA bR areverting...%%% should show b unknown and a back to normal? bmerging a%%% should show foo-bfoo-b%%% should show a removed and b addedA bR areverting...%%% should show b unknown and a marked modified (merged)? b%%% should show foo-bfoo-b