add Copy builder as a copy of Install

lib/rscons.rb

@@ -22,8 +22,9 @@ module Rscons
   # Names of the default builders which will be added to all newly created
   # {Environment} objects.
   DEFAULT_BUILDERS = [
-    :Command,
     :CFile,
+    :Command,
+    :Copy,
     :Directory,
     :Disassemble,
     :Install,

lib/rscons/builders/install.rb

@@ -54,6 +54,10 @@ module Rscons
         target if (target_is_dir ? Dir.exists?(target) : File.exists?(target))
       end
 
+
     end
+
+    class Copy < Install; end
+
   end
 end

spec/build_tests_spec.rb

@@ -859,6 +859,23 @@ EOF
       expect(lines).to eq(["Install inst.exe"])
     end
 
+    it "operates the same as a Copy builder" do
+      env = base_env.clone do |env|
+        lines
+        env.Copy("inst.exe", "simple.exe")
+      end
+      expect(lines).to eq(["Copy inst.exe"])
+      env.Copy("inst.exe", "simple.exe")
+      env.process
+      expect(lines).to eq([])
+      expect(File.exists?("inst.exe")).to be_truthy
+      expect(File.read("inst.exe", mode: "rb")).to eq(File.read("simple.exe", mode: "rb"))
+      FileUtils.rm("inst.exe")
+      env.Copy("inst.exe", "simple.exe")
+      env.process
+      expect(lines).to eq(["Copy inst.exe"])
+    end
+
     it "copies a file to the target directory name" do
       env = base_env.clone do |env|
         lines