Add xprop package (#3110)

packages/xprop.rb

+require 'package'
+
+class Xprop < Package
+  description 'Xprop is a property displayer for X.'
+  homepage 'https://www.x.org/'
+  version '1.2.3'
+  source_url 'https://x.org/releases/individual/app/xprop-1.2.3.tar.bz2'
+  source_sha256 'd22afb28c86d85fff10a50156a7d0fa930c80ae865d70b26d805fd28a17a521b'
+
+  depends_on 'xorg_lib'
+
+  def self.build
+    system './configure',
+           "--prefix=#{CREW_PREFIX}",
+           "--libdir=#{CREW_LIB_PREFIX}"
+    system 'make'
+  end
+
+  def self.install
+    system 'make', "DESTDIR=#{CREW_DEST_DIR}", 'install'
+  end
+end