Redox to implement POSIX signals in user space

Redox has received agrant to work on implementing POSIX-compatible signals. Thedraft design calls for them to be implemented nearly completely in user space.

So far, the signals project has been going according to plan, andhopefully, POSIX support for signals will be mostly complete by theend of summer, with in-kernel improvements to process management.After that, work on the userspace process manager will begin,possibly including new kernel performance and/or functionalityimprovements to facilitate this.