elements removed from DOM continue to live in DataTier's tracking maps

[gullerya]

Problem:
Removed elements are not cleared from the internal data-tier maps, causing multiple unnecessary update invocations on non-attached element and memory leak

Proposal:
Removed element MUST be removed from data-tier tracking maps

Relevant version/s (if any):
any up till 0.6.14

[gullerya]

fixed in version 0.6.15