#8 does not compile in Java 1.5 with default build.xml

[Sérgio Fernandes]

Need to add source="1.4" to compile using the provided buid.xml file. This is because of the following error:
[javac] berserk/src/pt/utl/ist/berserk/logic/filterManager/FilterInvocationTimingType.java:31: as of release 1.5, 'enum' is a keyword, and may not be used as an identifier
[javac] (try -source 1.4 or lower to use 'enum' as an identifier)
[javac] import org.apache.commons.lang.enum.ValuedEnum;
[javac] ^
[javac] 1 error