fix(change-detection): correctly process watch registration inside reaction FN.

Fix #678
fix(scope): fix null comparisons

Closes #646
chore(scope): remove assertion on destroy for perf reasons
chore(demo): move all demos into a single folder

fixes #624
Closes #688
fix(dirty_checking_change_detector): correctly truncate collection change record

Closes #692
perf(change-detection): optimize DirtyCheckingChangeDetector.collectChanges()

Closes #693
feat(blockhole): Change blockhole to have the insert / remove / move methods.

Closes #689