Add *_latest SQL tables for QtMetrics

Performance of QtMetrics should go up since
we now have tables containing only the latest data.
Obviously we need code changes to utilize
this new data.

Change-Id: I806ad2eb650cd08b3a7cf2f26eba1690e24a84fe
Reviewed-by: Juha Sippola <juhasippola@ovi.com>
Reviewed-by: Tony Sarajärvi <tony.sarajarvi@digia.com>