Change libffi.rb to not create static library

Correct dependencies

packages/libffi.rb

 require 'package'
 
 class Libffi < Package
-  version '3.2.1'
+  version '3.2.1-1'
   source_url 'ftp://sourceware.org/pub/libffi/libffi-3.2.1.tar.gz'
   source_sha1 '280c265b789e041c02e5c97815793dfc283fb1e6'
 
-  depends_on 'autoconf'
-  depends_on 'automake'
-
   def self.build
-    system "./configure", "--disable-debug", "--disable-dependency-tracking"
+    system "./configure", "--enable-shared", "--disable-static", "--with-pic", "--disable-debug", "--disable-dependency-tracking"
+    system "make"
   end
 
   def self.install
     system "make", "DESTDIR=#{CREW_DEST_DIR}", "install"
   end
+
+  def self.check
+    # system "make check"         # DejaGNU required
+  end
 end