If a decimal has 0 scale, treat it as a ruby int

0 scale means there's nothing after the decimal point
600 -> 600 examples
105 -> 104 failures
More correct schema parsing

It was having problems if there were multiple constraints on a column

600 -> 600 examples
104 -> 101 failures
Override alter_table_op_sql for fdbsql

this makes alter column work in a couple more instances

600 -> 600 examples
101 -> 98 failures
Support for application timezone

The application can have a timezone that's different from the db
so we need to convert back into the application's timezone when
reading out.

600 -> 600 examples
98  -> 94 failures
FDBSQL does not support usecs in the timestamps

only whole seconds here.

600 -> 600 examples
94 -> 91 failures