Upgrade java.jdbc to 0.3, use deprecated namespace.

This is the *bare minimum* we can do to support the latest `java.jdbc`.
(I.e., now we can gradually migrate Korma's code to use the new APIs)

I believe this is an alternate fix for #104.

Effectively, this commit also contains the following reversion:
> Revert "Merge pull request #193 from danenania/master"
>
> This reverts commit 51a69c7ded11e3d16e88ae79394d1ed0ac6b6a45, reversing
> changes made to 78ebc116348d183ccb740bbb9edb993dde609203.