fixed sockets on windows

This patch gets the basic forever operations working on Windows. It relies on [my version of forever-monitor](https://github.com/nodejitsu/forever-monitor/pull/70) to launch scripts.

Unix sockets are replaced by named pipes. Processes launched by forever on windows name their socket after their uid, like `\\.pipe\forever-sock\####`. Filenames in the pid directory are used to discover active pipes. The content of each file is checked in order to ignore pid files that have been set to `"0"`.
the function uses `(err, processes)`, much better to pass in `err` rather than undefined.