Add support for extracting 2006-01-02 formatted timestamps.

SQLite3 stores timestamps very naively -- they're completely untyped,
and can contain any value. The previous implementation always inserts
values in the 'datetime' format, and returns an error when attempting to
extract a field with a different format.

Some legacy databases, unfortunately, were generated using the 'date'
SQLite3 function, which produces rows in the '2006-01-02' format. This
patch adds a special case so that these rows can be extracted without
error.

sqlite3.go

@@ -27,6 +27,7 @@ import (
 )
 
 const SQLiteTimestampFormat = "2006-01-02 15:04:05"
+const SQLiteDateFormat = "2006-01-02"
 
 func init() {
 	sql.Register("sqlite3", &SQLiteDriver{})
@@ -313,7 +314,10 @@ func (rc *SQLiteRows) Next(dest []driver.Value) error {
 			if rc.decltype[i] == "timestamp" {
 				dest[i], err = time.Parse(SQLiteTimestampFormat, s)
 				if err != nil {
-					return err
+					dest[i], err = time.Parse(SQLiteDateFormat, s)
+					if err != nil {
+						return err
+					}
 				}
 			} else {
 				dest[i] = s