Add make task for building node bindings via Xcode

[mikemorris]

Think this should do it @kkaefer.

[mikemorris]

Looks like this is grabbing the wrong libuv/node headers, I hit this before testing a pre-release Node version for #2597, workaround was adding the node headers path to include_dirs in binding.gyp IIRC.

Node.js v4.2.1

libc++abi.dylib: terminating with uncaught exception of type std::runtime_error: libuv version mismatch: headers report 0.10.5, but library reports 1.7.5
Abort trap: 6

Node.js v0.12.7

libc++abi.dylib: terminating with uncaught exception of type std::runtime_error│
: libuv version mismatch: headers report 0.10.1, but library reports 1.6.1
Abort trap: 6

[kkaefer]

on node v0.10, it's failing with AttributeError: 'PBXAggregateTarget' object has no attribute ‘FrameworksPhase'. Looks like node-gyp includes -undefined dynamic_lookup in the libraries, which isn't something Xcode likes. Instead, that should be inLDFLAGS`.

[tmcw]

@mikemorris for the sake of documentation, why would someone want to run this instead of make node?

[kkaefer]

@tmcw You want to run make xnode so that you have an Xcode project that you can open in Xcode. This helps when debugging code, since you'll get a GUI debugger in the case of a crash.