DERBY-6488: Get rid of the EmbedSQLException class

Remove the newEmbedSQLException methods, since they don't produce
EmbedSQLExceptions anymore, and use the SQLExceptionFactory methods
instead.

Add a Throwable parameter to seeNextException() so that the root cause
will be shown when printStackTrace() is called on the top-level
exception.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1573934 13f79535-47bb-0310-9956-ffa450edef68