Update pom.xml

The configured dependency version for pact-array-datamodel should be the same as the one of the enclosing project.
Merge pull request #29 from aalexandrov/patch-1

Update pom.xml
Implemented reopenable hash join.
Fixed startup scripts to include extended hadoop dependencies in the classpath.
Backported ID Methods from 0.2.1
Made PactString appendable
Added setters for file statistics for easier subclassing
Generified binary and sequential i/o formats
added test-jar goal to pact-tests pom