Batch pending messages on network send

[karalabe]

In the Go binding, batching pending messages while sending over to the relay results in a 6-12% performance increase. Erlang side this would probably be a bit more murky, but it should be worthwhile nonetheless.

[karalabe]

Hmm, it didn't really do much. I guess the bottleneck is elsewhere and any speedup caused by this tuning remains unseens. Maybe I'll try it again a bit later after ironing out other kinks and performance issues.