revamp to mysql for gateway configuration and major code refactor

config/default.json.example

@@ -0,0 +1,38 @@
+{
+  "drachtio": {
+    "port": 3002,
+    "secret": "cymru"
+  },
+  "rtpengine": {
+    "host": "127.0.0.1",
+    "port": 22222
+  },
+  "logging": {
+    "level": "info"
+  },
+  "mysql": {
+    "host": "localhost",
+    "user": "jambones",
+    "password": "jambones",
+    "database": "jambones"
+  },
+  "trunks": {
+    "appserver": ["sip:172.38.0.11"]
+  },
+  "transcoding": {
+    "rtpCharacteristics" : {
+       "transport protocol": "RTP/AVP",
+       "DTLS": "off",
+       "SDES": "off",
+       "ICE": "remove",
+       "rtcp-mux": ["demux"]
+    },
+    "srtpCharacteristics": {
+       "transport-protocol": "UDP/TLS/RTP/SAVPF",
+       "ICE": "force",
+       "SDES": "off",
+       "flags": ["generate mid", "SDES-no"],
+       "rtcp-mux": ["require"]
+    } 
+  }
+}