Updated GRMustachio demo app to include Content Type popup menu

[KosmicTask]

Demo app can select HTML or Text content type.

[groue]

Hi Jonathan!

I'd rather not embed GRMustachio in the main distribution, despite its sensual evocation of the italian mustache, and the exciting introduction of a determined female warrior right at the moment one dreams of a roman pizza. You may like this blog-based comic "Sophia" : http://www.turbolapin.com/blog/?p=179 :-)

It'd rather not embed it because I'm not sure I could commit to the support. You know I like to keep the number of open issues low.

Here is a proposal that does not send GRMustachio to the limbs of useful yet unused software: ship it in its dedicated repository, under your @mugginsoft account: groue/GRMustache repo will link to it.

[KosmicTask]

Sorry about that last pull request. An interactive rebase went south late at night hence the noise.

GRMustachio, for what it is worth, lives on. I have included GRMustache as a submodule and link the app to the precompiled library binary in the submodule repo.

[groue]

Thanks Jonathan! You won the nicest user of 2013 prize (even though we're only in January) :-)