Thread safe changes
Add addValidID method; remove m_sortedIds
Change m_validIds.push_back call to addValidID
Change push_back/sort to lower_bound/insert
Added memory order hooks
Wrap atomic into if/else to keep ROOT build happy
Thread-safe Hcal DDD geometry
Merge pull request #1006 from ianna/hcal-ddd-geometry-fix

Geometry fixes -- Hcal ddd geometry fix