Add VERSION file for 0.5.0

Print a sensible error for Go < 1.7 (the "context" package is missing
there)

README.md

@@ -44,6 +44,16 @@ afterwards you'll find the binary in the current directory:
       restic [OPTIONS] <command>
     [...]
 
+You can easily cross-compile restic for all supported platforms, just supply
+the target OS and platform via the command-line options like this (for Windows
+and FreeBSD respectively):
+
+    $ go run build.go --goos windows --goarch amd64
+
+    $ go run build.go --goos freebsd --goarch 386
+
+The resulting binary is statically linked and does not require any libraries.
+
 More documentation can be found in the [user manual](doc/Manual.md).
 
 At the moment, the only tested compiler for restic is the official Go compiler.

VERSION

@@ -1 +1 @@
-0.5.0-rc.1
+0.5.0

build.go

@@ -291,6 +291,12 @@ func (cs Constants) LDFlags() string {
 }
 
 func main() {
+	ver := runtime.Version()
+	if strings.HasPrefix(ver, "go1") && ver < "go1.7" {
+		fmt.Fprintf(os.Stderr, "Go version %s detected, restic requires at least Go 1.7\n", ver)
+		os.Exit(1)
+	}
+
 	buildTags := []string{}
 
 	skipNext := false

doc/Manual.md

@@ -1,4 +1,4 @@
-Thanks for using restic. This document will give you an overview of the basic
+nhanks for using restic. This document will give you an overview of the basic
 functionality provided by restic.
 
 # Installing restic
@@ -43,6 +43,16 @@ $ cd restic
 $ go run build.go
 ```
 
+You can easily cross-compile restic for all supported platforms, just supply
+the target OS and platform via the command-line options like this (for Windows
+and FreeBSD respectively):
+
+    $ go run build.go --goos windows --goarch amd64
+
+    $ go run build.go --goos freebsd --goarch 386
+
+The resulting binary is statically linked and does not require any libraries.
+
 At the moment, the only tested compiler for restic is the official Go compiler.
 Building restic with gccgo may work, but is not supported.