POSIX file control and I/O support state

Functions:
- [x] mount
- [x] open
- [x] close
- [x] dup
- [x] dup2
- [x] read
- [x] write
- [x] ioctl
- [x] lseek
- [x] fstat
- [x] opendir
- [x] readdir
- [x] mknod
- [x] mkfifo
- [x] poll
- [x] fopen
- [x] fclose
- [x] fread
- [x] fwrite
- [x] fseek
- [x] fileno
- [ ] flock
- [x] getcwd
- [x] chdir
- [ ] mkdir
- [ ] rmdir
- [ ] rename
- [ ] unlink