added helper module
started implementing fun
added fun to root pom
added size, isUnique and isEmpty methods for PositionListIndex
Merge branch 'master' of ma2013@code.hpi.uni-potsdam.de:ma2013.git into ducc_dev
implemente getRawKeyError
Merge commit 'b4f8af40fd152ba2ee830d8f3e42f3c3eb204069' into HEAD
Merge remote-tracking branch 'origin/master' into fun_dev

Conflicts:
	algorithm_helper/src/main/java/de/uni_potsdam/hpi/metanome/algorithm_helper/data_structures/ColumnCombinationBitset.java
added empty constructor for PositionListIndex
removed LinkedLists from PLIBuilder
(where always accessed randomly)
using LongAVLTreeSet instead of LongOpenHashSet
removing values in PLIBuilder
improved PositionListIndex to use LongArrayLists as internal clusters
Merge branch 'ducc_dev' of ma2013@code.hpi.uni-potsdam.de:ma2013.git into ducc_dev
Merge remote-tracking branch 'origin/master' into ducc_dev
implemented getting distinct sorted columns from raw plis
Merge commit '89f29377963fab6b7606c28ac7cf0dc156b717bb' into HEAD
Merge commit 'cf4c85c96e91ef2774bdcdf03c91c49a439e4197' into HEAD
Merge remote-tracking branch 'origin/master' into ducc_dev
Merge commit '9096c5d769263fe92dc87e0b7f6506e8fe7efc42' into HEAD
Merge branch 'master' into ducc_dev
Merge commit '4dc10ffb616cd431944084a59b7841d99869a812' into HEAD