updated pty.cpp to the new Nan 2.0.0 signatures

[vlahupetar]

Hi Gottox,
I ran a script that updates the signatures inside pty.cpp to work with nan 2.0.9;
Let me just make clear that the last time i typed any cpp was 15 years ago and im not sure in the quality of my conversion.
either way the tests pass and i hope you will find this contribution useful.

a warning; there are 3 symbols that the compiler couldn't find so i commented them out: IUCLC, OLCLC and XCASE

Also i switched the signature of the o->Set method to use v8::Number instead of Integer as integer couldn't be resolved to the correct header method (maybe this opens a buffer overflow vulnerability)

Thanks,
Petar

[Gottox]

Nice, that's a good starting point. Unfortunartely this PR breaks older node.js versions, but I'm working on a fix.

Thanks :)