Use hsqldb memory protocol for jpa tests

currently appNG configures a hsqldb Server in the application-testcontext-jpa.xml

If the application environment is running another process (which might be a parallel build) on the same port, the tests will fail.

Instead, you can use an In-Process database on the memory protocol. This is faster and does not require an open port.

Since there is currently no configuration option to change the database type accordingly, I am overwriting the beans in my own testcontext:

<bean id="datasource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <constructor-arg type="java.lang.String" value="jdbc:hsqldb:mem://${database:hsql-testdb}" />
</bean>
 
<!-- overriding org/appng/testsupport/application-testcontext-jpa.xml server bean. No longer required -->
<bean id="server" class="java.lang.Object" /> 

see also: http://hsqldb.org/doc/guide/running-chapt.html#rgc_inprocess