Minor
[tests] Add set object to test-object.c
[tests] Start adding tests for hb-set.h

Fails now.  Fixing.
Protect sets in-error from further modication

Fixes test-set.c
[tests] Finish test-set.c

All passing now.
[OTLayout] Fix various introspection issues with ClassDef's

As reported by Jonathan Kew.
[OTLayout] Handle required_feature_index in collect_lookups
[OTLayout] Whitespace
[OTLayout] Fix feature iteration in collect_lookups

Previous logic was just wrong.
[OTLayout] Always collect default language system in collect_lookups

Not sure if this is the most desired behavior.  It's the most easily
defined though.
0.9.10