implement install and uninstall operations - close #82

add "prefix" construction variable - close #99
add InstallDirectory builder - close #100

build_tests/typical/install.rb

@@ -1,5 +1,14 @@
+project_name "install_test"
+
 build do
   Environment.new do |env|
-    env.Install("inst.exe", "install.rb")
+    env["CPPPATH"] += glob("src/**")
+    env.Program("^/program.exe", glob("src/**/*.c"))
+    env.InstallDirectory("${prefix}/bin")
+    env.Install("${prefix}/bin", "^/program.exe")
+    env.InstallDirectory("${prefix}/share")
+    env.Install("${prefix}/share/proj/install.rb", "install.rb")
+    env.Install("${prefix}/mult", ["install.rb", "copy.rb"])
+    env.Install("${prefix}/src", "src")
   end
 end