Move project version to file, add xS manual page

So far Go applications remain independent to handle Nix's inability
to easily combine them with the CMake part.

There is also no "install" target, because any packagers will want to
adjust installation paths manually, and there is no configure step.

xS/Makefile

@@ -2,16 +2,15 @@
 .SUFFIXES:
 AWK = env LC_ALL=C awk
 
-outputs = xS xS-version.go xS-replies.go
+outputs = xS xS-replies.go xS.1
 all: $(outputs)
 
-xS: xS.go xS-version.go xS-replies.go
-	go build -o $@
-xS-version.go: ../liberty/tools/cmake-parser.awk \
-	xS-gen-version.awk ../CMakeLists.txt
-	$(AWK) -f ../liberty/tools/cmake-parser.awk \
-		-f xS-gen-version.awk ../CMakeLists.txt > $@
+xS: xS.go ../xK-version xS-replies.go
+	go build -ldflags "-X 'main.projectVersion=$$(cat ../xK-version)'" -o $@
 xS-replies.go: xS-gen-replies.awk xS-replies
 	$(AWK) -f xS-gen-replies.awk xS-replies > $@
+xS.1: ../xK-version ../liberty/tools/asciiman.awk xS.adoc
+	env "asciidoc-release-version=$$(cat ../xK-version)" \
+		$(AWK) -f ../liberty/tools/asciiman.awk xS.adoc > $@
 clean:
 	rm -f $(outputs)