When following error message is shown, then it will get converted to the
correct Exception classs of NotNullConstraintViolationException:

  PDOException: SQLSTATE[HY000]: General error: 1364 Field '...' doesn't have a
  default value

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

fixes #2249

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

#714 - ignoring PDOExceptions on PDO#getAttribute(PDO::PGSQL_ATTR_DISABLE_PREPARES) as per https://bugs.php.net/bug.php?id=68351

#714 - Adding a test verifying that attribute `PDO::PGSQL_ATTR_DISABLE_PREPARES` is set when using pgsql on PHP 5.6+

Patch for OCI8Statement to support param[0] being null. Switched isset to array_key_exists. Added test that demonstrates the bug and confirms the fix.