swap buffertools out for buffer-equal

buffertools requires a compilation step and does some questionable
things like touching the prototype of the Buffer class. buffer-equal is
much less intrusive, much less code, and much less (infinity less, in
fact) native code.
Included buffer-equal implementation in lib.
Merge pull request #1 from tristanls/remove-buffertools

Included buffer-equal implementation in lib.
Merge pull request #3 from deoxxa/remove-buffertools

swap buffertools out for buffer-equal