Peformance increased in oidToString and dumpBytes1

When i used the lib i had some performance issues due to the all of the repeated string concatenation which made it slow according to my profiler. Hence i rewrote the oidToString and dumpBytes1 by using buffers instead. 

This resulted in a 35% performance increase for my test suit. How ever i don't really have any need for the dumpBytes method at all, and when it dumpBytes only returned i achived a 72.5% improvement. I assume this is since I do a fairly large number of parallel SNMP-requests using go processes. Over to the question is the dumpBytes really necessary or can it be made (or maybe already is) optional and can be disabled by using a flag?

Cheers
Mattias Folke