Add proxy support for curl and wget commands

lib/phantomjs.rb

@@ -5,6 +5,8 @@ module Phantomjs
   class UnknownPlatform < StandardError; end;
 
   class << self
+    attr_accessor :proxy_host, :proxy_port
+
     def available_platforms
       @available_platforms ||= []
     end

lib/phantomjs/platform.rb

@@ -51,7 +51,7 @@ def install!
         FileUtils.mkdir_p temp_dir
 
         Dir.chdir temp_dir do
-          unless system "curl -L -O #{package_url}" or system "wget #{package_url}"
+          unless system "curl -L -O #{package_url} #{curl_proxy_options}" or system "wget #{package_url} #{wget_proxy_options}"
             raise "\n\nFailed to load phantomjs! :(\nYou need to have cURL or wget installed on your system.\nIf you have, the source of phantomjs might be unavailable: #{package_url}\n\n"
           end
 
@@ -85,6 +85,18 @@ def install!
       def ensure_installed!
         install! unless installed?
       end
+
+      private
+
+      def curl_proxy_options
+        return '' if Phantomjs.proxy_host.nil? && Phantomjs.proxy_port.nil?
+        "-x #{Phantomjs.proxy_host}:#{Phantomjs.proxy_port}"
+      end
+
+      def wget_proxy_options
+        return '' if Phantomjs.proxy_host.nil? && Phantomjs.proxy_port.nil?
+        "-e use_proxy=yes -e http_proxy=#{Phantomjs.proxy_host}:#{Phantomjs.proxy_port}"
+      end
     end
 
     class Linux64 < Platform