Add base performance testcase and initial TypeConversionPerformanceTest

Add DbalPerformanceTestListener to collect & report performance test timing results.

Update docs dep script and readme to target Ubuntu 14.04

[DBAL-1219] Add missing functional driver test cases

[DBAL-1217] Fix retrieving the database name connected to for SQL Server

[DBAL-1218] Fix retrieving the database name connected to for SQL Anywhere

Fix tear down of some functional exception test cases

Override methods for sharding connection

Hotfix - #869 - fixes for type conversion logic

#869 - DBAL-1293 - Making sure `Type::getType('dateinterval')` retrieves a `DateIntervalType` instance