alfred: runtime configuration

Hi,

the alfred daemon has built-in capabilities for accepting runtime configuration. Network interfaces and alfred 'mode' (primary/secondary) settings can be modified via instructions sent over unix socket.

To make all settings configurable, the unix socket commands are extended to also support setting the batman-adv interface name at runtime. Network interfaces should no longer be required at startup as those can be configured at runtime.

All these runtime settings make understanding the current alfred configuration tricky. Therefore, alfred should be able to export its operating configuration via unix socket.

Cheers, Marek