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/unexpand.1

@@ -0,0 +1,41 @@
+.Dd October 8, 2015
+.Dt UNEXPAND 1
+.Os sbase
+.Sh NAME
+.Nm unexpand
+.Nd unexpand spaces to tabs
+.Sh SYNOPSIS
+.Nm
+.Op Fl a
+.Op Fl t Ar tablist
+.Op Ar file ...
+.Sh DESCRIPTION
+.Nm
+converts spaces to tabs in each
+.Ar file
+as specified in
+.Ar tablist .
+If no file is given,
+.Nm
+reads from stdin.
+.Pp
+Backspace characters are preserved and decrement the column count
+for tab calculations.
+.Sh OPTIONS
+.Bl -tag -width Ds
+.It Fl a
+Convert spaces to tabs everywhere, not just at the start of lines.
+.It Fl t Ar tablist
+Specify tab size or tabstops.
+.Ar tablist
+is a list of one (in the former case) or multiple (in the latter case)
+strictly positive integers separated by ' ' or ','.
+.Pp
+The default
+.Ar tablist
+is "8".
+.El
+.Sh SEE ALSO
+.Xr expand 1
+.Sh STANDARDS
+POSIX.1-2013.