GIRAPH-180 Prepare POM to allow for mvn deploy

This commit adds the apache parent POM as the parent of the
giraph-parent module.  This will allow the Giraph modules to pick up the
relevant settings necessary to perform mvn deploy on the giraph source
and start getting Maven SNAPSHOTS published.
GIRAPH-749: Update documentation according to the new EdgeOutputFormat API
GIRAPH-749: Update documentation according to the new EdgeOutputFormat API
GIRAPH-781. binary tarball lacks /bin and /conf directories
GIRAPH-783. giraph bin script should pick up giraph-core jar to pass to hadoop
GIRAPH-782. giraph script can't find GIRAPH_ENV_DIR when called via $PATH
Merge branch 'trunk' of https://github.com/apache/giraph into trunk
GIRAPH-796
GIRAPH-442
GIRAPH-757
GIRAPH-758
GIRAPH-758
GIRAPH-759
GIRAPH-760
GIRAPH-760
GIRAPH-793
Triangle finding implementation

Adds a simple triangle finding implementation to Giraph examples
Merge branch 'trunk' of https://github.com/apache/giraph into trunk
GIRAPH-797
GIRAPH-798: Upgrade Giraph to Java7 and fix all dependencies