gnu: Add unrar.

* gnu/packages/compression.scm (unrar): New variable.

gnu/packages/compression.scm

@@ -1128,3 +1128,21 @@ (define-public zpaq
                    ;; libzpaq.cpp contains a mix of public-domain and
                    ;; expat-licenced (or ‘MIT’) code.
                    license:expat))))
+
+(define-public unrar
+  (package
+    (name "unrar")
+    (version "0.0.1")
+    (source (origin
+              (method url-fetch)
+              (uri (string-append
+                    "http://download.gna.org/unrar/unrar-" version ".tar.gz"))
+              (sha256
+               (base32
+                "1fgmjaxffj3shyxgy765jhxwz1cq88hk0fih1bsdzyvymyyz6mz7"))))
+    (build-system gnu-build-system)
+    (home-page "http://download.gna.org/unrar")
+    (synopsis "RAR archive extraction tool")
+    (description "Unrar is a simple command-line program to list and extract
+RAR archives.")
+    (license license:gpl2+)))