Skip pg dependency on jruby
Allow jdbc SEQUEL_INTEGRATION_URL
Shell of a jdbc driver
Merge branch 'jdbc-support' into jdbc

Conflicts:
	sequel-fdbsql-adapter.gemspec
Correctly reference jdbc driver
Added section on running the unit tests with jdbc

(in case I get hit by a bus)
Moved Database methods to shared
Moved code into shared
Move PGError to pg specific code
Moved set_adapter_scheme to pg specific code
Fixed DatasetMethods module name
Moved connect & execute to pg specific code
initialize instance variables
require pg_types, so that it's there
Moved our exceptions to shared file
Only pg has to set in_transaction
Use CONVERTED_EXCEPTIONS constant

so that it can be different on JDBC vs PG
Moved fetch_rows methods to pg code
removed puts statements
Moved execute_prepared_statement to pg code

jdbc already handles this for us