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/nohup.1

@@ -0,0 +1,40 @@
+.Dd October 8, 2015
+.Dt NOHUP 1
+.Os sbase
+.Sh NAME
+.Nm nohup
+.Nd run command immune to hangups
+.Sh SYNOPSIS
+.Nm
+.Ar cmd
+.Op Ar arg ...
+.Sh DESCRIPTION
+.Nm
+runs
+.Ar cmd
+with the
+.Em HUP
+signal set to be ignored.
+.Pp
+If stdout is a terminal, it is appended to
+.Em nohup.out
+in the current working directory.
+If stderr is a terminal, it is redirected to stdout.
+.Sh EXIT STATUS
+.Bl -tag -width Ds
+.It 0
+.Ar cmd
+executed successfully.
+.It 1
+Internal error.
+.It 126
+.Ar cmd
+was found but could not be executed.
+.It 127
+.Ar cmd
+could not be found.
+.El
+.Sh SEE ALSO
+.Xr signal 7
+.Sh STANDARDS
+POSIX.1-2013.