GIRAPH-581: More flexible Hive output (majakabiljo)
GIRAPH-587: Refactor configuration options (nitay)
GIRAPH-588: GIRAPH-588: More flexible Hive input (majakabiljo)
Merge remote-tracking branch 'origin/trunk' into hive-perf

Conflicts:
	giraph-hive/src/main/java/org/apache/giraph/hive/output/AbstractVertexToHive.java
	giraph-hive/src/main/java/org/apache/giraph/hive/output/HiveVertexWriter.java
	giraph-hive/src/main/java/org/apache/giraph/hive/output/VertexToHive.java
	pom.xml
GIRAPH-597: Don't reuse vertex by default in SimpleHiveToVertex (majakabiljo)
Merge remote-tracking branch 'origin/trunk' into hive-perf

Conflicts:
	giraph-hive/src/main/java/org/apache/giraph/hive/HiveGiraphRunner.java
	giraph-hive/src/main/java/org/apache/giraph/hive/input/edge/AbstractHiveToEdge.java
	giraph-hive/src/main/java/org/apache/giraph/hive/input/edge/HiveEdgeReader.java
	giraph-hive/src/main/java/org/apache/giraph/hive/input/edge/HiveToEdge.java
	giraph-hive/src/main/java/org/apache/giraph/hive/input/vertex/AbstractHiveToVertex.java
	giraph-hive/src/main/java/org/apache/giraph/hive/input/vertex/HiveToVertexEdges.java
	giraph-hive/src/main/java/org/apache/giraph/hive/input/vertex/HiveVertexReader.java
	giraph-hive/src/main/java/org/apache/giraph/hive/input/vertex/SimpleNoEdgesHiveToVertex.java
	giraph-hive/src/main/java/org/apache/giraph/hive/output/AbstractVertexToHive.java
Merge remote-tracking branch 'origin/trunk' into hive-perf

Conflicts:
	giraph-hive/src/main/java/org/apache/giraph/hive/input/edge/SimpleHiveToEdge.java
	giraph-hive/src/main/java/org/apache/giraph/hive/input/vertex/SimpleHiveToVertex.java