Fix column comment (#392)

Support multi-line comments on columns.

Author: soroushj

internal/dinosql/gen.go

@@ -1163,7 +1163,7 @@ func (e *{{.Name}}) Scan(src interface{}) error {
 {{if .Comment}}{{comment .Comment}}{{end}}
 type {{.Name}} struct { {{- range .Fields}}
   {{- if .Comment}}
-  // {{.Comment}}{{else}}
+  {{comment .Comment}}{{else}}
   {{- end}}
   {{.Name}} {{.Type}} {{if $.EmitJSONTags}}{{$.Q}}{{.Tag}}{{$.Q}}{{end}}
   {{- end}}

internal/dinosql/kotlin/gen.go

@@ -824,7 +824,7 @@ enum class {{.Name}}(val value: String) {
 data class {{.Name}} ( {{- range $i, $e := .Fields}}
   {{- if $i }},{{end}}
   {{- if .Comment}}
-  // {{.Comment}}{{else}}
+  {{comment .Comment}}{{else}}
   {{- end}}
   val {{.Name}}: {{.Type}}
   {{- end}}