[MONDRIAN-1819]  Mondrian generates timestamp predicates for date fields

1819 is a bug that applied to Mondrian 3.x.  Bringing over the test to lock in functionality in lagunitas as well.
This commit also fixes the RolapSchema.getStar() method, which formerly would always return null.
Merge pull request #200 from mkambol/lagMon1819

[MONDRIAN-1819]  Mondrian generates timestamp predicates for date fields