Feature delete nodes with outlets

[gunterhager]

Deletes nodes in XLIFF that are connected to outlets. Ideally this should be implemented with an option switch.

[tomekc]

Thanks for the pull request @gunterhager, I merged it in my private fork and it helped me a lot. I found, however, that I want to keep UIButtons which have outlets (for example, in order to disable/enable them). I concluded that supressing only outlets to UILabels should be enough:

https://github.com/tomekc/fame/commit/9184cfc22ed1aa13267625641f8512cafcf751cf