Address bug in default template install process (Solr4Generator).

Don't require the jettywrapper option to be passed to the generator to install jettywrapper (it is already checked before running that generator).

Add the templates directory as a source_root so the generator can access to jetty.yml

lib/generators/blacklight/solr4_generator.rb

@@ -3,17 +3,18 @@
 
 module Blacklight
   class Solr4Generator < Rails::Generators::Base
+
+    source_root File.expand_path('../templates', __FILE__)
+
     desc <<-EOS
       This generator makes the following changes to your application:
        1. Installs jettywrapper into your application
        2. Adds rsolr to your Gemfile
     EOS
 
     def install_jettywrapper
-      return unless options[:jettywrapper]
       gem "jettywrapper".dup, ">= 2.0"
-
-      copy_file "config/jetty.yml"
+      copy_file "config/jetty.yml", "config/jetty.yml"
 
       append_to_file "Rakefile",
         "\nZIP_URL = \"https://github.com/projectblacklight/blacklight-jetty/archive/v4.10.4.zip\"\n" \