[DBAL-835] Quote old column name in rename column SQL

Properly instantiate var and fix spelling

HHVM nightly and PHP 5.6 in builds

[DBAL-825] Drop default constraints before altering column type on SQL Server

[DBAL-843] Fix reverse engineering LOB type column types in MySQL

Fix integer 0 default value reverse engineering on SQL Anywhere

Fix reverse engineering quoted table names on PostgreSQL

Fix type hint

Change weird way of adding an entry to SplObjectStorage

[DBAL-834] Fix order by with aggregate function(s) for limit/offset queries on SQL Server

Remove unused imports

Fix driver exception conversion for newer SQLite versions

Fix FQNs

Improve param name

Add missing @param tags

Don't return the return values of methods that do not return anything

Fix incorrect reference to PDO in DB2Statement

Fix incorrect type hint in TableDiff