Updating a schema should introduce also schema creation statements in the generated SQL

Fix rst list

The current version is not displayed correctly at
http://docs.doctrine-project.org/projects/doctrine-dbal/en/latest/reference/portability.html

Improve QueryBuilder docs

* Remove aliases from examples where they make no sense
* Fixed copy paste error

Update docs to include warning when using object type with PostgreSQL

Update docs to relfect the changes to QueryBuilder::from made in #646

Make the $alias parameter in the `from` method optional

Split the methods in TestUtil more and improve naming

foreach AS -> foreach as

Add parameter types in doc

Added missing @throws

Fix escaping of column name for specific alter table case

Unit tests currently only cover SQLite, MySQL and PostgreSQL.

Tests for other platforms have been marked as incomplete.

improved sqlserver 'doModifyLimitQuery' select-from pattern

with assertEquals

Allow to connect without a dbname param

The PDO connection allow the instantiation of the connection even if the dbname
parameter isn't present. This change is there to make sure both behave the same way.

When changing the length of a field, the column name needs to be escaped
properly.

Fix pg boolean conversion