Follow-up to issue #81: remove SysV shared memory IPC altogether

This change removes a long standing kernel requirement and architectural
mishap in the design of Finit v1.  It is no longer necessary to include
CONFIG_SYSVIPC in the kernel to use Finit and its command line tool
initctl.  It is also no longer possible to connect to the internals of
PID 1 using shmat(), the initctl tool has already been updated to use
the domain socket API.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

doc/TODO.md

@@ -21,9 +21,6 @@ can also be used.
 General
 -------
 
-* Remove shm, let `initctl` call `api.c` for each `svc_t` instead of
-  opening up the inner parts of PID 1 to other processes.  Also, this
-  would prevent issues like #81 from happening.
 * Add support for timed shutdown in Finit, including cancelled shutdown.
 * SysV init and systemd use SIGUSR1 to restart their FIFO/D-Bus.  Add
   API restart to SIGHUP callback for the same functionality in Finit.