Update tracee's stack pointer before transfering data into tracee's stack.

I'm not sure this is required for remote transfer, but the Linux
kernel might not allow page faults below the stack pointer:

    Accessing the stack below %sp is always a bug.

    -- linux-3.1/arch/x86/mm/fault.c

Ref.: https://github.com/cedric-vincent/PRoot/issues/73
Fix name of proot-ed processes.

By default, proot-ed processes got their name replaced by the name of
the loader.  For examples:

    $ proot-v4.0.3 ps
      PID TTY          TIME CMD
     7885 pts/11   00:00:00 bash
     8131 pts/11   00:00:00 proot
     8132 pts/11   00:00:00 ld-2.17.so

    $ proot-v5.0.0 ps
      PID TTY          TIME CMD
     7885 pts/11   00:00:00 bash
     7916 pts/11   00:00:00 proot
     7917 pts/11   00:00:00 prooted-7916-Jb

This old behavior was confusing and it is now fixed:

    $ ./src/proot ps
      PID TTY          TIME CMD
     7885 pts/11   00:00:00 bash
     8585 pts/11   00:00:00 proot
     8586 pts/11   00:00:00 ps