Don't Close() on connection error, retry every minute

Don't Close() on connection error, retry every minute
Fix a _() that should have been N_()
Username & Password are non-advanced settings
Warn user with interaction if Username is bad or not set
Handshake only if there is something to submit
Get rid of hexa() for printf("%02x")
Replace % 256 and / (2^x) by bitwise operations : & 0xff and >> x
Don't cancel submission of song if user has paused playing
Code for new meta_engine (not enabled yet)