panic() cleanup.

this change
   - makes panic() variadic, doing full printf() formatting -
     no more NO_NUM, and no more separate printf() statements
     needed to print extra info (or something in hex) before panicing
   - unifies panic() - same panic() name and usage for everyone -
     vm, kernel and rest have different names/syntax currently
     in order to implement their own luxuries, but no longer
   - throws out the 1st argument, to make source less noisy.
     the panic() in syslib retrieves the server name from the kernel
     so it should be clear enough who is panicing; e.g.
         panic("sigaction failed: %d", errno);
     looks like:
         at_wini(73130): panic: sigaction failed: 0
         syslib:panic.c: stacktrace: 0x74dc 0x2025 0x100a
   - throws out report() - printf() is more convenient and powerful
   - harmonizes/fixes the use of panic() - there were a few places
     that used printf-style formatting (didn't work) and newlines
     (messes up the formatting) in panic()
   - throws out a few per-server panic() functions
   - cleans up a tie-in of tty with panic()

merging printf() and panic() statements to be done incrementally.

lib/libsys/Makefile

@@ -103,7 +103,6 @@ SRCS=  \
 	env_prefix.c \
 	fkey_ctl.c \
 	tsc_util.c \
-	report.c \
 	read_tsc.S \
 	read_tsc_64.c \
 	ser_putc.c \
@@ -111,6 +110,7 @@ SRCS=  \
 	sys_hz.c \
 	timing.c \
 	profile_extern.c \
-	profile.c
+	profile.c \
+	vprintf.c
 
 .include <minix.lib.mk>