package: remove "engines" section

It's dumb... doesn't do anything...
nan wip
binding: more nan refactoring progress

Down to just 1 build error now...
package: update "nan" to v1.1.0
biding: attempt at refactoring for nan v1.1.0 API
binding: fix NanAssignPersistent() call
binding: attempt at making writeObject() work with nan
binding: use memset() to set the writeObject() persistent reference

Fixes the segfaulting :)
Merge pull request #14 from TooTallNate/refactor/nan

Refactor - use `rvagg/nan` v1.1.0