Fixed MySQL setup script to use lower-case table name to match the references in the file. This had caused an error on systems where case sensitivity matters.

Removes redundant and forever dangling connection

Wrapped the call to System.getProperty in a try/catch to anticipate
the SecurityException that can result from accessing system properties
in the presence of a SecurityManager (e.g. in an applet sandbox).

Avoid NPE when getting CodeSource

CodeSource can be null - add a check to avoid NPE

The DataSourceConnectionSource.start() method opens a new connection
only to determine whether or not the discoverConnectionProperties()
should be called. This is unnecessary since that method will perform
the same check and issue a very similar warning. A more serious
problem is that the connection is never closed.

This commit removes the use of this extra connection completely. I
think this is the last issue in need of a fix before LOGBACK-376 can
be closed.