This allows users to benefit from the same flexible machinery when using
SQLite as when using MySQL, and also allows to add some more default
cast rules too.
When default values are used in SQLite they are of course using their
SQLite representation, which might not be compatible with the PostgreSQL
target data type we're casting to. Make it so that the default values
are transformed too, as we already do in the MySQL case.
See #100.
In SQLite it's possible to define columns using type names such as
"smallint unsigned" or "short integer", without any changes to the way
those data types are handled, given its "dynamic typing" features.
Improve the pgloader casting machinery for SQLite to handle those cases.
This issue has been re-opened with blob instead of double. Semi-blindly
implement support for the blob type with an image data type.
Disturbingly enough when tested with non-binary data SQLite was
returning strings rather than byte vectors, tripping up the transform
function that sure expects byte vectors.
