Add scheme48 package

Scheme48 is a Scheme byte-code interpreter.

Tested as working on XE500C13-K01US.

packages/scheme48.rb

+require 'package'
+
+class Scheme48 < Package
+  description 'Scheme byte-code interpreter'
+  homepage 'http://s48.org/'
+  version '1.9.2'
+  source_url 'http://s48.org/1.9.2/scheme48-1.9.2.tgz'
+  source_sha256 '9c4921a90e95daee067cd2e9cc0ffe09e118f4da01c0c0198e577c4f47759df4'
+
+  binary_url ({
+  })
+  binary_sha256 ({
+  })
+
+  def self.build
+    system "./configure", "--prefix=#{CREW_PREFIX}"
+    system "make"
+  end
+
+  def self.install
+    system "make", "DESTDIR=#{CREW_DEST_DIR}", "install"
+  end
+end