Move getRecentHistory tests into test_PIS_getRecentHistory.js.
Move clearRecentVisits tests into test_PIS_clearRecentVisits.js
Remove clearRecentVisits and getRecentHistory tests from test_PlacesInterestsStorage.js
Made getRecentHistory daysAgo interpretation exlusive, 0 - nothing, 1 - today, 2 - todays+yesterday, etc...