texinfo 5.1 fixes for heimdal-1-5-branch

This pull request allows me to build Heimdal 1.5 on Fedora 19 (texinfo 5.1). In the Fedora Heimdal package, Alexander (@abokth) and I are using these four patches that are not yet on heimdal-1-5-branch.

Now that #35 has been merged, all four of these are already on master. It would be great to get these cherry-picks merged to the heimdal-1-5-branch as well, so we can stop carrying these patches in the Fedora Heimdal package.