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/tftp.1

@@ -0,0 +1,32 @@
+.Dd October 8, 2015
+.Dt TFTP 1
+.Os sbase
+.Sh NAME
+.Nm tftp
+.Nd trivial file transfer protocol client
+.Sh SYNOPSIS
+.Nm
+.Fl h Ar host
+.Op Fl p Ar port
+.Op Fl x | c
+.Ar file
+.Sh DESCRIPTION
+.Nm
+is a client that implements the trivial file transfer protocol over
+either IPv4 or IPv6 as specified in RFC 1350.
+It can be used to transfer files to and from remote machines.
+.Sh OPTIONS
+.Bl -tag -width Ds
+.It Fl h Ar host
+Set the remote hostname.
+.It Fl p Ar port
+Set the remote port.
+It defaults to port 69.
+.It Fl x
+Extract a file from the server.
+This is the default if no flags are specified.
+Output goes to stdout.
+.It Fl c
+Create a file on the server.
+Input comes from stdin.
+.El