Externalize Active MQ storage directory in application-context.xml

[donaldoakes]

In mdw-common/src/META-INF/mdw/spring/application-context.xml, change the hardwired amq:broker dataDirectory to use property syntax like the values in the MDWDataSource bean. The default dataDirectory when no property is specified should be the existing relative location (../activemq-data).

[jbrojdeCTL]

New properties:
activemq:
location: activemq-data # Has to be relative to startup directory - default=../activemq-data
port: 61619 # default=61618
maxConnections: 10 # Max connections in JMS pool - default=8

Unfortunately, there's a problem with Spring Expression Language and the activemq schema that means the expression cannot be the first thing in the value, meaning the following doesn't work:

dataDirectory="#{T(com.centurylink.mdw.config.PropertyManager).getProperty('mdw.activemq.location', '../activemq-data')}">

But it does work if you add a leading space to it (but then the specified path doesn't work because it starts with a space), so instead, we're specifying ./ before the expression like this:

dataDirectory="./#{T(com.centurylink.mdw.config.PropertyManager).getProperty('mdw.activemq.location', '../activemq-data')}">

This means that the specified value via property has to be relative to the startup directory of the application. This is still better than having to override the entire application-context.xml file