Driver: whitespace and identiation fixes in readPacket()

Signed-off-by: Martin Zenzes <martin.zenzes@dfki.de>
Driver: add comment in readPacket(), nice texts in throws

use a "no data" wording instead of "timeout"

Signed-off-by: Martin Zenzes <martin.zenzes@dfki.de>
Driver: handle the "timeout exception" in the noData+noTimeout case

using the "TimeoutError::FIRST_BYTE" exception type to indicate no data
could be read with a timeout of zero. given a custom string describing
the cause for the exception.

Signed-off-by: Martin Zenzes <martin.zenzes@dfki.de>
Merge pull request #1 from rock-drivers/dont_throw_without_timeout

Cleanup of timeout behaviour and error messages in readPacket