[#1748] Support custom MySQL driver parameters for "db" configuration
parameter
[#1765] make more generic so it now works with normal hibernate entities as well as JPABase
[#1767] avoid a nullpointer bug when the stack is null
[#1728] Use MySQL ping if apropriate, a SELECT 1 otherwise

Conflicts:
	framework/src/play/db/DBPlugin.java
	framework/src/play/db/jpa/JPAPlugin.java
Merge branch 'lighthouse-1748-master-patch' of github.com:tazmaniax/play1 into tazmaniax-lighthouse-1748-master-patch

Conflicts:
	framework/src/play/db/DBConfig.java
[#1760] make fields more visible so we can subclass Promise with our own unique promise to gain functionality
[#1759] add exception log
[#1735] Create TypeUnbinder in order to implement "unbind method"
[#1735] Fix TypeUnbinder test the wrong class
[#1735] add return to unbind method