no need to export another Column constant in AS400
avoid the Column regressions in 1.3.12 caused by backporting too much from master
closes #603
align SQLite's column class resolution with others in 1.3
make MySQL pass our tests under 5.6
Conflicts:
	test/db/mysql/connection_test.rb
handle ("hacked") date/time/timestamp conversion from the JDBC side on 4.2
work done by @prathamesh-sonpatki based on @sgrif's suggestion
appraise latest 4.2
a "fast" attempt to bring 4.2 compatibility to PG but seems it's not the right way

Postgres will be the trickiest to handle multiple AR support with 4.2 ... as always
prepare for 1.3.13 (duea Column constant regression in 1.3.12)
Merge branch '1-3-stable'

* 1-3-stable:
  prepare for 1.3.13 (duea Column constant regression in 1.3.12)
  a "fast" attempt to bring 4.2 compatibility to PG but seems it's not the right way
  appraise latest 4.2
  handle ("hacked") date/time/timestamp conversion from the JDBC side on 4.2 work done by @prathamesh-sonpatki based on @sgrif's suggestion
  make MySQL pass our tests under 5.6 Conflicts: 	test/db/mysql/connection_test.rb
  align SQLite's column class resolution with others in 1.3
  avoid the Column regressions in 1.3.12 caused by backporting too much from master closes #603
  no need to export another Column constant in AS400