libsys: various updates

- move system calls for use by services from libminlib into libsys;
- move srv_fork(2) and srv_kill(2) from RS and into libsys;
- replace getprocnr(2) with sef_self(3);
- rename previous getnprocnr(2) to getprocnr(2);
- clean up getepinfo(2);
- change all libsys calls that used _syscall to use _taskcall, so as
  to avoid going through errno to pass errors; this is already how
  most calls work anyway, and many of the calls previously using
  _syscall were already assumed to return the actual error;
- initialize request messages to zero, for future compatibility
  (note that this does not include PCI calls, which are in need of a
  much bigger overhaul, nor kernel calls);
- clean up more of dead DS code as a side effect.

Change-Id: I8788f54c68598fcf58e23486e270c2d749780ebb

lib/libsys/Makefile

@@ -9,12 +9,16 @@ SRCS+=  \
 	alloc_util.c \
 	assert.c \
 	asynsend.c \
+	checkperms.c \
+	copyfd.c \
 	ds.c	\
 	env_get_prm.c \
 	env_panic.c \
 	env_parse.c \
 	env_prefix.c \
 	fkey_ctl.c \
+	getepinfo.c \
+	getprocnr.c \
 	getticks.c \
 	getsysinfo.c \
 	getuptime.c \
@@ -22,6 +26,7 @@ SRCS+=  \
 	kprintf.c \
 	kputc.c \
 	kputs.c \
+	mapdriver.c \
 	optset.c \
 	panic.c \
 	safecopies.c \
@@ -33,6 +38,8 @@ SRCS+=  \
 	sef_ping.c \
 	sef_signal.c \
 	sqrt_approx.c \
+	srv_fork.c \
+	srv_kill.c \
 	stacktrace.c \
 	sys_abort.c \
 	sys_clear.c \
@@ -84,9 +91,13 @@ SRCS+=  \
 	vm_fork.c \
 	vm_info.c \
 	vm_map_phys.c \
+	vm_memctl.c \
 	vm_notify_sig.c \
 	vm_umap.c \
 	vm_procctl.c \
+	vm_query_exit.c \
+	vm_set_priv.c \
+	vm_update.c \
 	vprintf.c
 
 .if ${MKPCI} != "no"