Browser tests no longer mandate hidden items are removed from the DOM

Fixes #908 - tests no longer mandate hidden items are removed from the DOM
Closes #790 - these were implementations that implemented routing via hiding items, rather than removing from the DOM

Regressions:
#949 - discovered that exoskeleton is badly broken
#858 - added typescript-backbone (might not be a regression, more likely missed earlier)

Updated knownIssues based on recent updates to puremvc, react, soma etc ...