Add node pre gyp path to search

[bwknight877]

This change adds the default node-pre-gyp module_path to search like how sqlite3 does their native node module (and others too I'm sure)

This will search in ./lib/binding/{node_abi}-{platform}-{arch}

It looks like this also addresses Issue 11

Also it looked like there is a missing right paren, fixed that

[bwknight877]

In an effort to make libxmljs use the ./lib/binding/{node_abi}-{platform}-{arch} directory for its native node module, I opened this PR to add this path to the default search paths for node-bindings

libxmljs PR 459 for reference
they were using node-bindings to load xmljs.node from ./build/Release/

[TooTallNate]

Thanks Bryan, merged this in 68dae57.