can't work on node 4+

[lawrence-peng]

my mac's environment is

• node v4.2.1
• node-gyp v3.0.3

[Willyham]

Looks like this might be because tchannel needs to bump farmhash version @Raynos

[kriskowal]

We also suspect that bufrw depends details of the node 0.10 era Buffer, but have not yet investigated.