Fixed max length of MySql TEXT type declaration

This should be 65535 (2 ^ 16 - 1) in stead of 65532.
Modified docblock to show the max lengths.
Add support for all MySql BLOB type declarations

Choose between TINYBLOB, BLOB, MEDIUMBLOB and LONGBLOB based on the length of the field.
Behaves the same way as the TEXT type declaration.
Added tests for TEXT and BLOB type declarations
Move magic numbers to constants
Merge branch 'jappie-master-rebase'