D-Net

#1257 dropping schema generation related hacks in all PIG modules, switching to literal schema parameters

#1257 renaming 'eu.dnetlib.iis.avro.map.output.value.class' property (which become obsolete) required by CollapserReducer to 'collapser.reducer.schema.class'.

#1257 dropping schema generation related hacks in all map-reduce modules, switching to literal schema parameters

#1176 updating description

#1176 introducing side products removal in multiple_input_collapser by maintaining sideproducts_removal flag

#1133 dropping useless workfing_dir creation for pig nodes

#1022 introducing PMC extracted document metadata collapser removing duplicates before sending output to PMC citation ingestion module

#577 renaming origins to matched and ingested

#577 fixing PMC citations collapser by executing toString() on text when retrieving map value

updating job.properties