Invalidate _switchPathCache when switchPath changes.
Create Alternation compontent, move switchPath from Repetition to Alternation.
Inherit blueprint from the Repetition.

No idea if it works, no idea how to test.
Remove all switchPath related code from Repetition.
Add the missing parts to alternation.meta.
Fix meta file.
Merge pull request #1380 from NV/repetition-arguments

Move switchPath from Repetition into a subclass