Minor tweaks to Eclipse dot files
Merge remote branch 'origin/test_implementation' into test_implementation
Added 'candidate comment' at single item level
Further tidying of TSController
Added comment handling + N/L fix to TSController:

* We now support submission of candidate comments, respecting
the effective value of ItemSessionControl
* Fixed bug in selectItemNonlinear() when selecting an item
whose state has ended (e.g. because only 1 attempt was allowed)
Added engine support for comments in tests
Minor tweaks to date storage in state XML
Minor tweak to test part exit event recording