Make parseDateTime and friends (format..., parseBinary...) public

[oakad]

It is possible that for whatever reason "parseTime" is not specified in the connection string (indeed, it is disabled by default). However, users still need to parse the various time values returned by MySQL and usually do so via all kinds of not quite correct ways using time.Parse.

Would not it make all the sense to export the existing time handling functions for the benefit of the users?