This commit allows create call flow extension with some feature code (e.g. `*401`)
Then on the phone you can configure BLF like `flow+*401` and use `call_flow_subscribe` to
track current status of this call flow. BLF like `*401` will also works but only if
use `call_flow_monitor` script.
Also it is possible dial `flow+*401` as well as `*401` to toggle call flow state.
Move code to turn on/off BLF to separate function.
```Lua
presence_in.turn_lamp( toggle == "false",
call_flow_feature_code.."@"..domain_name,
call_flow_uuid
);
```
Close temp file in call_flow_monitor because on Windows it prevent to remove it.
Connect/release to database inside call_flow_monitor loop.
Check successful connection to database in call_flow_monitor loop so monitor did not crash
if connection temporary lost.