Building arrowpad and hellotr examples pollutes my source tree

I'm repeatedly seeing git reporting

	examples/linguist/arrowpad/arrowpad_fr.ts
	examples/linguist/arrowpad/arrowpad_nl.ts
	examples/linguist/hellotr/hellotr_la.ts

as stray files in my qttools checkout. I can only suppose these are generated as part of doing a build. Files generated in the course of a build should go in the build tree, not the source tree. If they really cannot be created in the build tree (that's probably a bug in the generator or build process; but, if that can't be fixed, ...) they should be overtly listed in a relevant .gitignore file.