Change Oracle "drop column" syntax

DBAL-112, DBAL-113 - Implement AbstractPlatform::getAlterSequenceSQL() and fix comparator code for sequences

DDC-887 - Fix problem with MySQL renaming of foreign keys columns. The FK has to be dropped, then column renamed, then readded

Remove AllTests approach to PHPUnit and work with a phpunit.xml.dist from the top level of the repository.

Fix bug in DropSchemaSQLCollector dropping tables before sequences which can cause constraint errors

MySqlPlatform PHPDoc Update

Unsigned is missing on the column data.

[PostgreSqlPlatform] Fixed truncate

Changed boolean conversion values

[DBAL-123] Added ability to remove SQL logger after it has been set.

DBAL-119