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/which.1

@@ -0,0 +1,44 @@
+.Dd October 8, 2015
+.Dt WHICH 1
+.Os sbase
+.Sh NAME
+.Nm which
+.Nd locate programs in the path
+.Sh SYNOPSIS
+.Nm
+.Op Fl a
+.Ar name ...
+.Sh DESCRIPTION
+.Nm
+looks for each
+.Ar name
+in the
+.Ev PATH
+directories, stopping at the first match and printing
+the full path to stdout.
+.Sh OPTIONS
+.Bl -tag -width Ds
+.It Fl a
+Don't stop at the first match and search all
+.Ev PATH
+directories.
+.El
+.Sh EXIT STATUS
+.Bl -tag -width Ds
+.It 0
+Each
+.Ar name
+was found.
+.It 1
+At least one
+.Ar name
+was not found.
+.It 2
+No
+.Ar name
+was found.
+.It 3
+An error occurred.
+.El
+.Sh SEE ALSO
+.Xr environ 7