mysql: update mysql driver to latest master

The latest master implements the ColumnType interface.

See https://github.com/go-sql-driver/mysql/issues/495

This removes the custom code in the vendor folder that
did a ColumnType mapping.

vendor/github.com/go-sql-driver/mysql/driver.go

@@ -4,7 +4,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
 // You can obtain one at http://mozilla.org/MPL/2.0/.
 
-// Package mysql provides a MySQL driver for Go's database/sql package
+// Package mysql provides a MySQL driver for Go's database/sql package.
 //
 // The driver should be used via the database/sql package:
 //
@@ -22,6 +22,11 @@ import (
 	"net"
 )
 
+// watcher interface is used for context support (From Go 1.8)
+type watcher interface {
+	startWatcher()
+}
+
 // MySQLDriver is exported to make the driver directly accessible.
 // In general the driver is used via the database/sql package.
 type MySQLDriver struct{}
@@ -52,13 +57,13 @@ func (d MySQLDriver) Open(dsn string) (driver.Conn, error) {
 	mc := &mysqlConn{
 		maxAllowedPacket: maxPacketSize,
 		maxWriteSize:     maxPacketSize - 1,
+		closech:          make(chan struct{}),
 	}
 	mc.cfg, err = ParseDSN(dsn)
 	if err != nil {
 		return nil, err
 	}
 	mc.parseTime = mc.cfg.ParseTime
-	mc.strict = mc.cfg.Strict
 
 	// Connect to Server
 	if dial, ok := dials[mc.cfg.Net]; ok {
@@ -81,6 +86,11 @@ func (d MySQLDriver) Open(dsn string) (driver.Conn, error) {
 		}
 	}
 
+	// Call startWatcher for context support (From Go 1.8)
+	if s, ok := interface{}(mc).(watcher); ok {
+		s.startWatcher()
+	}
+
 	mc.buf = newBuffer(mc.netConn)
 
 	// Set I/O timeouts