Add date_created, date_updated to “base” tables (v1.4)

[bradfordcondon]

sounds self explanatory The issue description is this which looks unrelated to me

4. Change 'feature.seqlen' to a bigint to accommodate longer sequences. Great.

One more thing that come to my mind is to have a datetime column for most of the central tables for example in the pub table. It simply allows me to have the state of row with making changes to the core tables or adding additional linking tables and application logic. The idea is similar to what ruby on rails framework add to every table once you run the migration through it(date_created, date_updated).