new protein level filter: filter for the number of proteins which are
unique for the reported protein group (i.e. it allowas absolutely
undistinguishable groups)
Merge branch 'master' of https://github.com/mpc-bioinformatics/pia.git

Conflicts:
	src/de/mpc/pia/modeller/report/filter/protein/NrGroupUniquePeptidesPerProteinFilter.java