PostgreSQL allows the user to set the application_name is connecting
to database. It is useful for monitoring purposes.
Currently one could just manually add 'application_name=foo' to DSN,
but having a parameter eases setting it using DoctrineBundle.

The schema's name in the alter session command must not be quoted
https://docs.oracle.com/cd/B28359_01/server.111/b28310/general009.htm

fixes #1352

also refactors URL path evaluation into smaller methods

fixes #1106

fix usage of PDO::PGSQL_ATTR_DISABLE_PREPARES for pdo_pgsql extension setups not built from PHP core

fixes #2249

fixes #1339
closes #921

When creating sqlite connections from a url with DriverManager, pass the 'path' key the driver expects instead of the 'dbname' key other drivers expect.

According to comment https://github.com/doctrine/dbal/pull/854#issuecomment-126935212

Features and changes:
* jsonb can be used with: options={"jsonb"=true}
* OVER is no longer reserved
* LATERAL is now reserved