Allow PHP7 failure on Travis again

Removing 2.4.x from readme

Fix usage of PDO::PGSQL_ATTR_DISABLE_PREPARES for edge case pdo_pgsql setups

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

fixes #2249

[DBAL-1779] Fix string column type declarations with whitespace on SQLite

wheee

fixes #1339
closes #921

Fix SchemaManagerFunctionalTestCase::testDropsDatabaseWithActiveConnections() on Oracle

Minor edit to fix formatting glitches

The first paragraph of section 6.1 has some minor formatting errors (see http://docs.doctrine-project.org/projects/doctrine-dbal/en/latest/reference/transactions.html#transaction-nesting)
Removing a couple of spaces fixes the problem.

Rebuild SQLServerPlatform::doModifyLimitQuery again to use a CTE

Avoid rewrapping Docrine\DBAL\Exception\DriverException with nested drivers

Use shorter table names - Oracle allows max 30 characters

Use shorter table names - Oracle allows max 30 characters - http://docs.oracle.com/cd/B19306_01/server.102/b14200/sql_elements008.htm#sthref723

Fixing method name 'rollBack', which was documented as 'rollback'

Remove submodule entries & improve test setup

Fix typo

add sslrootcert connection option to pdo_pgsql driver