Applied patch from Kim Ho to fix a regression against a 7.4 server. The result

Applied patch from Kim Ho to fix a regression against a 7.4 server.  The result
of transaction isolation level changed from uppercase to lower case between 7.3 and 7.4.  In testing, a regression was also fixed in this area when talking to
a 7.2 server due to changes in how notice messages are processed in the current
code.

 Modified Files:
 	jdbc/build.xml jdbc/org/postgresql/core/BaseStatement.java
 	jdbc/org/postgresql/jdbc1/AbstractJdbc1Connection.java