fix blob type mapping in SQL Server platform
Merge pull request #450 from deeky666/DBAL-122

[DBAL-122] Fix BLOB type mapping in SQL Server platform
[DBAL-562] Prevent autoincrement columns from creating CREATE SEQUENCE statement on down migrations
Merge pull request #345 from chEbba/comparator-autoincrement-sequence

Prevent autoincrement columns from creating CREATE SEQUENCE statement