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.
Extended comments in nephele config file.
Minor cleanup and corrections in API classes.
Fixed webfrontend plan display for workset iterations.
Split pact-compiler project between compiler and its unit tests and the compiler end-to-end tests with example programs.
Merged pull request #35 (salting hashes for multi-column keys)
Fixed hash join tests with after salting hashes.
Fixed dependencies of pact compiler tests.
KMeans example point input format parses negative numbers.
Disabled recovery by default.
New kmeans data generator.
Made sure user code class loaders are used for cloading user code classes.
Implemented CoGroup join with solution set.
Cleaned up connected components example and tests.
Fixed bug in pact-record-output-emitter partitioner.
Fixed class loading during transmission of user-defined aggregators through the iteration events.
Minor cleanup in examples.