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.
Fix config and start scripts to work on Windows/cygwin

Also fix WebInterfaceServer.java to properly check whether path
is absolute on Windows.

Default directory entries in nephele-user.xml and pact-user.xml
are now commented out because java code will load proper default.