Move track/program info handling to server

[trosh]

client requests /radios/getInfo.php, receives a json in the format

[
    "nova" : {
        "artist" : "Francis Cabrel",
        "title" : "Je L'aime A Mourir"
    }, ...
]

and parses it to find info for each station, if available.

getInfo.php checks how long ago it last fetched info (getInfoLastTimeStamp), and either fetches info from files (radioName, ...), or from the web and into the files (+ update getInfoLastTimeStamp) before returning aggregated info.