config/git: import suckless sbase

i currently use the output of sha512sum in several
places of xbmk, which is a bit unreliable in case
output changes.

other cases where i use util outputs in variables
are probably reliable, because i'm using mostly
posix utilities in those.

to mitigate this, i now import suckless sbase, which
has a reasonable sha512sum implementation.

*every* binary it builds is being placed in build.list,
because i'll probably start using more of them.

for example, i may start modifying the "date"
implementation, adding the GNU-specific options that
i need as mentioned on init.sh

i'm importing it in util/ because the sha512sum
util is needed for verifying project sources, so
if sbase itself is a "project source", that means
we can into a chicken and egg bootstrapping problem.

this is sbase at revision:
055cc1ae1b3a13c3d8f25af0a4a3316590efcd48

Signed-off-by: Leah Rowe <leah@libreboot.org>

util/sbase/printf.1

@@ -0,0 +1,33 @@
+.Dd October 8, 2015
+.Dt PRINTF 1
+.Os sbase
+.Sh NAME
+.Nm printf
+.Nd print formatted data
+.Sh SYNOPSIS
+.Nm
+.Ar format
+.Op Ar arg ...
+.Sh DESCRIPTION
+.Nm
+writes formatted data according to
+.Ar format
+using each
+.Ar arg
+until drained.
+.Pp
+.Nm
+interprets the standard escape sequences \e\e, \e', \e", \ea, \eb, \ee,
+\ef, \en, \er, \et, \ev, \exH[H], \eO[OOO], the sequence \ec, which
+terminates further output if it's found inside
+.Ar format
+or a %b format string, the format specification %b for an unescaped string and
+all C
+.Xr printf 3
+format specifications ending with csdiouxXaAeEfFgG, including variable width
+and precision.
+.Sh STANDARDS
+POSIX.1-2013.
+.Pp
+The possibility of specifying 4-digit octals is an extension to that
+specification.