Add byobu package

packages/byobu.rb

+require 'package'
+
+class Byobu < Package
+  description 'Byobu is a GPLv3 open source text-based window manager and terminal multiplexer.'
+  homepage 'http://byobu.org/'
+  version '5.119'
+  source_url 'https://launchpadlibrarian.net/322131788/byobu_5.119.orig.tar.gz'
+  source_sha1 '1d8d07da4c94c4adeb662a7f8b33fe02482d9839'
+
+  def self.build
+    system './configure'
+    system 'make'
+  end
+
+  def self.install
+    system "make", "DESTDIR=#{CREW_DEST_DIR}", "install"
+  end
+end