Updating MAGE module meta data to support next gen data

[scottcain]

Updating table descriptions to generalize mage to include next-gen sequencing experiments and other possible analyses instead of microarray only. This is a suggested topic for the 2018 PAG hackathon.

A related topic is the suggested modifications for the 1.4 Chado release: https://docs.google.com/document/d/1t_Jb4XxUPtgGRSKtznsqvjTjmR4vpFHPQROMQ0OZK9A/edit?usp=sharing

[bradfordcondon]

proposed changes from Staton group https://docs.google.com/document/d/168Wz--WYGOmIxcLWt4NDh0lplOAh5Na7hCP-rLC4bd8/edit?usp=sharing