storage/mysql: add database connection limit (#1288)
storage/mysql: add database connection limit (#1288)

Default to no connection limit.

AlCutter/trillian,gdbelvin/trillian,RJPercival/trillian,Martin2112/trillian,daviddrysdale/trillian,gdbelvin/trillian,AlCutter/trillian,google/trillian,RJPercival/trillian,daviddrysdale/trillian,gdbelvin/trillian,Martin2112/trillian,Martin2112/trillian,google/trillian,daviddrysdale/trillian