Added SemVer versioning to project

Makefile

@@ -1,22 +1,22 @@
-# git diff-index --quiet HEAD --        // returns 1 if UNclean
-# you can also use "go generate" to trigger a script that fills in a "version.go" file ???
-# check for set SYSTEMROOT envvar --> windows
-
-LD_FLAGS = -s -w -H windowsgui
+LD_FLAGS = -H windowsgui
+LD_FLAGS_RELEASE = -s -w
 
 build:
 	go build -ldflags="$(LD_FLAGS)"
 
+# Needs: go get github.com/ahmetb/govvv
+release:
+	govvv build -ldflags="$(LD_FLAGS) $(LD_FLAGS_RELEASE)"
+
 # Needs: go get github.com/akavel/rsrc
 resources:
 	rsrc -manifest gunarchiver.manifest -ico gunarchiver.ico -o rsrc.syso
 
 clean:
 	rm gunarchiver.exe
-	rm rsrc.syso
 
-dist:
-	zip gunarchiver.zip gunarchiver.exe README.md LICENSE
+dist: release
+	zip gunarchiver-bin.zip gunarchiver.exe README.md LICENSE VERSION
 
 test:
 	go test ./...

archive/archive_test.go

@@ -1,3 +1,7 @@
+// Copyright 2017 Martin Planer. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package archive_test
 
 // Tests for archive extraction.

archive/tar/tar.go

@@ -10,9 +10,8 @@ import (
 	"os"
 	"strings"
 
-	"compress/gzip"
-
 	"archive/tar"
+	"compress/gzip"
 
 	"github.com/martinplaner/gunarchiver/archive"
 )

main.go

@@ -24,6 +24,8 @@ func main() {
 	var extractErr error
 	var uiErr error
 
+	PrintVersion()
+
 	if len(os.Args) != 2 {
 		fmt.Printf("Usage: %s <archive>\n", os.Args[0])
 		return

version.go

@@ -0,0 +1,19 @@
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+var (
+	Version    string = "undefined"
+	BuildDate  string = "N/A"
+	GitCommit  string = "undefined"
+	GitBranch  string = ""
+	GitState   string = ""
+	GitSummary string = ""
+)
+
+func PrintVersion() {
+	fmt.Printf("%s version %s\nbuild %s\ndate %s\n\n", os.Args[0], Version, GitCommit, BuildDate)
+}