[#104] Support PolymorphicComponents as language pragma

[jan-christiansen]

Resolves #104

[tomjaguarpaw]

Thanks!

[tomjaguarpaw]

Sorry, I made the wrong suggestion in my review comment. version needs to be reinstated, with the original version number.

[jan-christiansen]

I should probably have caught that.

Are there any guidelines on history rewriting in pull requests in this projects? That is, do you squash the pull request anyway, should I use force push to combine the commits into a single commit? Do you want to keep the history of the pull request?

[tomjaguarpaw]

That's no problem. Personally I prefer well-curated commits, which in this case means a squash (since it's so small). I don't mind if you do that or I do that.

[tomjaguarpaw]

Thanks!