Process TODO

[robotman2412]

• Make it possible to partially munmap an mmap'ed region
• Add support for controlling TTYs
• Add traditional fork and exec system calls for MMU systems
• Convert pcreate to POSIX-style spawn system call
• Add chroot support
• Add working dir support
• Add envvars
• Add interpreted executable support (#!/path/to/interpreter args-for-interpreter)
• Kill processes to free memory if OOM