[derby] final frontier for handling non-string vals assigned to string columns
fix JNDI tests - as it's Derby empty insert statement do not work on AR 4.0
manual test should not really needed ... if someone's using it scream :) !
align tests with "native" (MRI) mysql2 adapter
update (simple) tests to match MRI behaviour + avoid string-suble on AR 4.0
as it's getting quite difficult to support this hack of our inherited from 1.2.x

we should still add a deprecation warning but hopefully we can slowly eliminate code such as (for now at least with the latest AR it won't work) :

`exec_query 'SELECT * FROM u WHERE id = ?', [ [column, 1]]`

as this is not supported by ActiveRecord and is quite dangerous ...
while there's really no need for it esp. with arel
start moving test modules out of simple.rb
do not use the deprecated SQL.gsub syntax with explain + binds test
handle `sql_literal?` with all adapters while quoting + to_sql on exec_xxx
more (test) updates to be able to run tests agains SQLite/Postgres on MRI
add MRI driver gems to all appraised gemfiles
[postgres] fix `extension_enabled?` to work with raw boolean values
only suble_binds if not an arel passed + allow to turn bind subling off
need to make sure we always execute a prepared query with `table_exists?`
re-build jar (due Derby updates - using 1.6.8)