Support naming environments - close #140

build_tests/typical/Rsconscript

@@ -0,0 +1,6 @@
+build do
+  Environment.new(name: "typical") do |env|
+    env["CPPPATH"] += glob("src/**")
+    env.Program("^/typical.exe", glob("src/**/*.c"))
+  end
+end

build_tests/typical/clone_and_name.rb

@@ -0,0 +1,9 @@
+build do
+  base_env = Environment.new do |env|
+    env["CPPPATH"] += glob("src/**")
+  end
+
+  base_env.clone(name: "typical") do |env|
+    env.Program("^/typical.exe", glob("src/**/*.c"))
+  end
+end