copy function

[rmxhaha]

I think your copy function is one off.
if I try to copy

var buf = buffer.create(32);
buffer.copy( buffer.from( 'abcdefg' ), buf, 0, 0, 5 );
console.log( buffer.to( buffer.subarray( buf, 0, 5 ) ) );

it outputs 'abcde'
isn't it suppose to be 'abcdef' ?
because that's index 0 1 2 3 4 5

it's kinda strange that beginning ( index 0) is inclusive but last index (index 5) isn't

I kinda doubt this issue is gonna be resolved looking at last commit
I'll try to hack into the code and perhaps fork it somehow
:) I don't know how send fixes to repository that isn't mine just yet...