[TIMOB-10473] Tooling: apidoc validate.py gets in endless loop when two files can't be parsed

If TextField.yml and TextArea.yml are malformed and cannot be parsed by the YAML parsing engine, validate.py goes nuts. It could be that other file combinations can make this happen, but we noticed it with TextField.yml and TextArea.yml, so we'll stick with those two for these testing notes.

Testing Notes

* Edit both apidoc/Titanium/UI/TextField.yml and apidoc/Titanium/UI/TextArea.yml. * Break them both on purpose by putting a space in front of their name: keys on line 2. * Save them. * Run python apidoc/validate.py. In the fail case, you'll see runtime error stack traces and then a ton of warnings,... forever. When testing the fix, validate.py should simply stop with an error.