For Doctrine DBAL >=2.6.

Requested in issue #2.

Other changes include:

• PSR-1 and PSR-2 brush-up.
• Moving towards PHP 7.1 syntax, including strict types.
• More exceptions are now thrown with more sensible explanations of what went wrong. This is to counter hard-to-understand error messages, which are a bi-product of the code getting allowed to run too far. Also, ibase likes to segmentaion fault/core dump, which completely ruins stack traces and thus debugging.
• More test coverage.
• Integration tests now all run in separate processes (@runTestsInSeparateProcesses).