some thinking about what happens when a server crashes
Merge branch 'master' into unplanned_failover_thoughts

Conflicts:
	lib/active_record/connection_adapters/mysql_flexmaster_adapter.rb
	test/ar_flexmaster_test.rb
further on unplanned failover
update comments
checkpoint a lot of work around unplanned failover
Merge branch 'master' into unplanned_failover_thoughts
rescue ActiveRecord errors too

I guess we won't talk, again, about activerecord's error handling.
overhaul the test suite

- change the current-connection detection to be clearer
- try to make tests order independant (with up! and down!)
- expand upon lost-master tests
back to stock mysql_isolated_server
add rescues and logic around Can't connect errors

(for connections where reconnect: true is set).  (is this even
advisable?)
debugger is 2.0, i guess, rev mysql_isolated_server
update the gemfiles
add unplanned failover thoughts markdown
upgrade debugger
upgrade gems, remove 2.0 compat for now