Add undocumented oci8 persistent connections

The oci8 driver can connect using oci_pconnect to make persistent connections. Doctrine has support for this if the persistent boolean value is set to true in the documentation. However, this information was not documented.

Revert conditional PGSQL & MARIADB change

Removes all sudo items (except hhvm which currently still requires sudo)
reverting the other simpler matrix attempt

Enhance phpdoc of QueryBuilder::setParameter()

[DBAL-2644] Fix fetchAll(PDO::FETCH_COLUMN) on DB2 with Portability wrapper

Simplify Travis Build matrix

Make functional sqlanywhere driver tests conditional

SQLAnywhere corrections for DSN generation and persistent connections

Fix result cache and PDO connection test on pdo_sqlsrv

Fix closing statement cursor on pdo_sqlsrv if not executed yet

[DBAL-2637] Fix closing prepared statement cursor with LOB column on Oracle

Fix dropping inuse databases on SQL Server and Oracle

Fix the reuse of a statement on sqlsrv with explicit bindValue()

Tear down active transactions in functional test cases

Fix drivers' exec() method to not execute via prepared statements

[DBAL-2623] Fix Generic SQL Sharding Support documentation example

HHVM testing needs to be in PHP 7 mode

Fix fetching last insert ID for sequences on SQL Server

Fix date diff test