Enables mssql support (#383)

* Enables mssql support

Port of dlobs work in gogs.
Enables options in index.js
Enables MSSQL as a database option in go.
Sets ID to 0 on initial migration. Required for
MSSQL insert statements.

Signed-off-by: Beau Trepp <beautrepp@gmail.com>

* Vendors in denisenkom/go-mssqldb

Includes golang.org/x/crypto/md4
as this is required by go-msssqldb

Signed-off-by: Beau Trepp <beautrepp@gmail.com>

vendor/github.com/denisenkom/go-mssqldb/log.go

@@ -0,0 +1,23 @@
+package mssql
+
+import (
+	"log"
+)
+
+type Logger log.Logger
+
+func (logger *Logger) Printf(format string, v ...interface{}) {
+	if logger != nil {
+		(*log.Logger)(logger).Printf(format, v...)
+	} else {
+		log.Printf(format, v...)
+	}
+}
+
+func (logger *Logger) Println(v ...interface{}) {
+	if logger != nil {
+		(*log.Logger)(logger).Println(v...)
+	} else {
+		log.Println(v...)
+	}
+}