textpair: change compareTo, so it ignores whitespace part, and sort key
with two parts as larger than one with just one
FusionCombiner: added combiner which writes fusion key on top of regular
keys
FusionExecution: fusion executes mapper only write to first key in text
pair, added combiner class
FusionCreateToSeqFile: changed reducer count to 1, write single field
two times instead of 1, changed write key order to write smaller key
first