Fix JDBCConnection null logger errors, fix JDBCConnectionTest

Hello,

Here is the code that fixes the following: 

* JDBCConnection NullPointerException when you tried to log errors while the logger was null
* JDBCConnectionTest fixed the testAddUploadedTable case, where it would allways fail due to the way checkUploadedTableDef is created
* Also tweaked the sample votable to highligth a SQLite create table corner case

The rest of the pull request is optional and only directly related to what I'm doing with taplib, but you should consider adding to your libs the servlet api, catalina.jar (or drop this one, as you have a very light dependency on the thing), junit (and hamcrest if using JUnit 4), and optionally the drivers for both sqlite and postgresql (seeing you use them for tests.

Best regards and good job with the work for version 2.0.