Add haproxy (1.7.2) package

HAProxy is a reliable, high-performance TCP/HTTP load balancer.

Tested on XE50013-K01US (x86_64).

packages/haproxy.rb

+require 'package'
+
+class Haproxy < Package
+  version '1.7.2'
+  source_url 'http://www.haproxy.org/download/1.7/src/haproxy-1.7.2.tar.gz'
+  source_sha1 'b022485e28b96b673e3116a69d8922cb7367a81f'
+  
+  depends_on "openssl"
+  depends_on "pcre"
+
+  def self.build
+    system "make TARGET=linux26 USE_OPENSSL=1 USE_PCRE=1 USE_ZLIB=1"
+  end
+
+  def self.install
+    system "make", "DESTDIR=#{CREW_DEST_DIR}", "install" 
+  end
+end