Fix startup crash where Hydra controllers are not properly plugged in

Crash occurs if the left controller is plugged in but right one isn't.
Merge pull request #3048 from ctrlaltdavid/fix_hydra_crash

Fix startup crash where Hydra controllers are not properly plugged in
Set minimum angular size too model selection
Added angular size limit to hydras too.
Merge pull request #3049 from Atlante45/make_selection_range_infinite

Make selection range infinite
Merge branch 'master' of https://github.com/highfidelity/hifi into modify_foreign_avatars_attachments
Added class to handle MetaMessages
Switched else if to switch case
Removed random break