Closing a pin will automatically check and close any pin that where being watch for interrupt.
Created two new Interface and hid implementation details as much as possible.
Basicly imported Dave Cheney's code from http://github.com/davecheney/gpio
this ensures cleaner abstractions/code and will ensure that the produced binary is as small as possible. a convenience package is provided to easily load all hosts easily: "github.com/kidoman/embd/host/all"