Changes the join conditions.

Join the tables de_rna_seq_annotation and de_subject_rna_data on the
transcript_id and probeset_id. These are varchar columns.
Readds maxSize constraint for transcriptId field
Uses id/name mapping in stead of the weaker id/column
Adds missing assay test
Merge branch 'temp' into rnaseqv2
Merge pull request #2 from thehyve/changes_join_condition_for_RNA_SEQ

Changes the join conditions.