AGAT-v0.4.0

• add new script agat_sq_add_attributes_from_tsv.pl (Fix #44)
• fix regression introduced in AGAT-v0.3.0 that involved high slowness in statistics (issue #45 and #43 ).
• Update agat_convert_sp_gff2gtf.pl (Fix #46) => fix GTF output by skipping bioperl. Now all attribute's values are quoted and gene_id and transcript_id attributes come first in the attribute list.
• do not change output name anymore in agat_sq_manage_IDs.pl (keep name provided by the user intact)
• Fix link in Readme (PR #42)