Refactor for more flexibility

* Move from gcfg to toml configuration because gcfg was too restrictive
* Implemented gateway which has support multiple in and out bridges.
* Allow for bridging the same bridges, which means eg you can now bridge between multiple mattermosts.
* Support multiple gateways

vendor/github.com/BurntSushi/toml/cmd/toml-test-decoder/main.go

@@ -0,0 +1,90 @@
+// Command toml-test-decoder satisfies the toml-test interface for testing
+// TOML decoders. Namely, it accepts TOML on stdin and outputs JSON on stdout.
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"path"
+	"time"
+
+	"github.com/BurntSushi/toml"
+)
+
+func init() {
+	log.SetFlags(0)
+
+	flag.Usage = usage
+	flag.Parse()
+}
+
+func usage() {
+	log.Printf("Usage: %s < toml-file\n", path.Base(os.Args[0]))
+	flag.PrintDefaults()
+
+	os.Exit(1)
+}
+
+func main() {
+	if flag.NArg() != 0 {
+		flag.Usage()
+	}
+
+	var tmp interface{}
+	if _, err := toml.DecodeReader(os.Stdin, &tmp); err != nil {
+		log.Fatalf("Error decoding TOML: %s", err)
+	}
+
+	typedTmp := translate(tmp)
+	if err := json.NewEncoder(os.Stdout).Encode(typedTmp); err != nil {
+		log.Fatalf("Error encoding JSON: %s", err)
+	}
+}
+
+func translate(tomlData interface{}) interface{} {
+	switch orig := tomlData.(type) {
+	case map[string]interface{}:
+		typed := make(map[string]interface{}, len(orig))
+		for k, v := range orig {
+			typed[k] = translate(v)
+		}
+		return typed
+	case []map[string]interface{}:
+		typed := make([]map[string]interface{}, len(orig))
+		for i, v := range orig {
+			typed[i] = translate(v).(map[string]interface{})
+		}
+		return typed
+	case []interface{}:
+		typed := make([]interface{}, len(orig))
+		for i, v := range orig {
+			typed[i] = translate(v)
+		}
+
+		// We don't really need to tag arrays, but let's be future proof.
+		// (If TOML ever supports tuples, we'll need this.)
+		return tag("array", typed)
+	case time.Time:
+		return tag("datetime", orig.Format("2006-01-02T15:04:05Z"))
+	case bool:
+		return tag("bool", fmt.Sprintf("%v", orig))
+	case int64:
+		return tag("integer", fmt.Sprintf("%d", orig))
+	case float64:
+		return tag("float", fmt.Sprintf("%v", orig))
+	case string:
+		return tag("string", orig)
+	}
+
+	panic(fmt.Sprintf("Unknown type: %T", tomlData))
+}
+
+func tag(typeName string, data interface{}) map[string]interface{} {
+	return map[string]interface{}{
+		"type":  typeName,
+		"value": data,
+	}
+}