NLSR

Currently NLSR maintains a set of separate classes for encoding data structures to TLV format. In my view, this is not an optimal approach. This is a simple problem to solve, since the process is similar each time, and is a basic transformation to a string. This can be accomplished by a free function, for example, or by a method that employs a common helper function. Further, continually duplicating TLV classes is not a tenable long-term design paradigm -- as the number of published things increases, complexity of these structures will increase, leading to double the maintenance work. We should aim to minimize the code surface, and only add complexity when necessary.