Changed 'implements' by 'extends' on SQLAzureFederationsSynchronizer

Changed 'implements' by 'extends' because AbstractSchemaSynchronizer is a class not an interface (and Eclipse PDT shows a warning that say that "The type SQLAzureFederationsSynchronizer must implement the inherited method processSqlSafely, processSql" but those methods are already implemented on AbstractSchemaSynchronizer).

Fixed some phpdoc

Added a missing method in the Constraint interface

Fix unsigned columns in MySql

Unsigned column properties were never set. In consequence all migrations diff were trying to change the column definition when it was already changed.

Fixed a typo in a method name

improved exception messages when driver error occurs

Fixes error with ORA-03131 in oracle stored procedures

Used the placeholder in the command help for the name

Fixing breaking test provoke by #172

Fixed typos

Fix DebugStack->stopQuery to prevent unnecessary timings when disabled.

[DDC-1657] Prevent autoincrement sequences from creating DROP SEQUENCE statements because of old/new schema missmatch.

previous changes in bindparam function

bindParam function expects length parameter for oci_bind_by_name oci8

This reverts commit 17a265d9.

driver function