Fix escaping of column name for specific alter table case

When changing the length of a field, the column name needs to be escaped
properly.
bug fix for db2 v10 new column def of syscat.columns.default
remove debug echo statements and use more phpunit built in facilities where available
more compat with php 5.3
add test to verify null cast in boolean type
resolves #632 Fix null cast in boolean type in Postgres platform
refs #632 Remove is_null to be consistent with doctrine coding standard
remove unsuitable test
Revert "remove unsuitable test"

This reverts commit 58d73c023ab8fadfc1f71e3728c74439d59ab7df.

I deleted the wrong file lol...
remove testwhich was unsuitable for test suite
Added unit test for changing column lengths

Unit tests currently only cover SQLite, MySQL and PostgreSQL.

Tests for other platforms have been marked as incomplete.
Merge pull request #627 from PVince81/pgsql-altertable-keyword

Fix escaping of column name for specific alter table case
Update PostgreSqlPlatform.php

Add new line after an IF statement to be consistent with the coding standard
Merge pull request #1 from doctrine/master

Update from master
Test to check null conversion with boolean type

Add functional test to check null conversion with boolean type. This test required NULL to be allowed in the table column.
Added missing @throws
Add parameter types in doc
Merge pull request #639 from JeroenDeDauw/th

Added missing @throws
Merge pull request #640 from JeroenDeDauw/pt

Add parameter types in doc
Merge pull request #2 from doctrine/master

Update from master repository