Updating a schema should introduce also schema creation statements in the generated SQL

The PDO connection allow the instantiation of the connection even if the dbname
parameter isn't present. This change is there to make sure both behave the same way.

When changing the length of a field, the column name needs to be escaped
properly.

reverted @deeky666 suggestion. Since it failed on testBooleanNullConvertsToPHPValue test. 
with message Failed asserting that true is null.
Since I moved this code from BoolenType::convertToPHPValue in the first place, I presume the code there correct.

updated convert function  to include uppercased values

Description fix

fixed parameter order in conditions

Changes after Ocramius comments

fixed bug when $item was set as bool true value
added 'off' literal

Changed to call platform specific Boolean conversion