[docs] no documentation on sys.db.Connection

I'm migrating some data out of XML files into a sqlite database and I'm glad that Haxe has built-in support for everything I need.

One problem is, I couldn't find helpful information on how to use the Connection interface, except in this example which is MySQL specific and predates the unified interface of sys.db.Connection: http://old.haxe.org/doc/sys/db/mysql

It would be nice to get doc comments on the Connection functions.