Moved core extensions to Net::BER. Documented.

lib/net/ber/core_ext/bignum.rb

@@ -0,0 +1,19 @@
+module Net::BER::Extensions::Bignum
+  ##
+  # Converts a Bignum to an uncompressed BER integer.
+  def to_ber
+    result = []
+
+    # NOTE: Array#pack's 'w' is a BER _compressed_ integer. We need
+    # uncompressed BER integers, so we're not using that. See also:
+    # http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/228864
+    n = self
+    while n > 0
+      b = n & 0xff
+      result << b
+      n = n >> 8
+    end
+
+    "\002" + ([result.size] + result.reverse).pack('C*')
+  end
+end