TelegramParser.parse should receive raw bytestring

[ndokter]

A small refactoring of the way DSMRProtocol and SerialReader feed data into TelegramParser.parse. This currently consists of a list of strings.

The preferred solution is that TelegramParser.parse will accept a single bytestring as outputted by the meter without any alterations. This removes any form of logic in the clients themselves and will also sort issues with line endings (see pull request #15)

[ndokter]

Thinking about going for str instead of bytes so it's easier to integrate into python 2.x.