ResearchLog. Track time of log statements

Log statements are now recorded with a timestamp.  This is important for filtering out statements
not part of words that are sampled when spaces are inserted automatically.

multi-project commit with Change-Id: I68221a2528045d25632aef4bb716f92a4f4a56a4

Change-Id: I9f49c36391e1e1773b6d4876d7387c893024f87b