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
remove unsuitable test
Revert "remove unsuitable test"

This reverts commit 58d73c023ab8fadfc1f71e3728c74439d59ab7df.

I deleted the wrong file lol...
remove testwhich was unsuitable for test suite
Support for Partial Indexes for PostgreSql and Sqlite

Support for Partial Indexes was available in Doctrine 1 following
http://www.doctrine-project.org/jira/browse/DC-82. This commit
reintroduce support for Doctrine 2. We use the same syntax with an
optionnal "where" attribute for Index and UniqueConstraint.
Fix code style as mentionned in PR comments
Refactor partial into options array

This coherent with what is done for Table. All platform specific things
are grouped into an options array. Eventually flags should be migrated
into options as well.
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
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
foreach AS -> foreach as
Merge pull request #642 from JeroenDeDauw/as

foreach AS -> foreach as
Split the methods in TestUtil more and improve naming
Merge pull request #643 from JeroenDeDauw/TestUtill

Split the methods in TestUtil more and improve naming