Support more complex property types in container configuration

It might sometimes be helpful to support arbitrary property lists within an arquillian configuration, such as when we want to make it possible to pass properties to the underlying container implementations, but that have no effect on the behavior of the arquillian-container-implementation itself.

This is not to replace, but to augment the current configuration capability, such that we can provide something like the following in an arquillian.xml:

<container qualifier="someQualifier" default="true">
<configuration>
<propertyList name="somePropertyName">
<propertyEntry name="somePropertyEntryName" type="java.lang.String" value="someValue" />
<propertyEntry name="somePropertyEntryName2" type="java.lang.Integer" value="1234" />
...
</propertyList>
<property name="someOtherProperty">someValue</property>
</configuration>
</container>