[PATCH v3] Fix crash when a stencil routine is missing

[Patrick McCarty]

Hello,

The third revision of my patch set (Patch Set 5) is on Rietveld:

http://codereview.appspot.com/83046/show

The change from Patch Set 4 is the generalization of
-dwarning-as-error.  Note that this is a series of 8 commits that
contain more in-depth commit summaries.  They can be found here:

http://repo.or.cz/w/lilypond/patrick.git?a=shortlog;h=refs/heads/stencil-update

I welcome any comments/criticism.

Thanks,
Patrick