io: options for disabling addons

Closes Homebrew/homebrew#14142.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Formula/io.rb

@@ -7,6 +7,9 @@ class Io < Formula
 
   head 'https://github.com/stevedekorte/io.git'
 
+  option 'without-addons', 'Build without addons'
+  option 'without-python', 'Build without python addon'
+
   depends_on 'cmake' => :build
   depends_on 'ossp-uuid'
   depends_on 'libevent'
@@ -22,6 +25,16 @@ class Io < Formula
 
   def install
     ENV.j1
+    if build.include? 'without-addons'
+      inreplace  "CMakeLists.txt",
+        'add_subdirectory(addons)',
+        '#add_subdirectory(addons)'
+    end
+    if build.include? 'without-python'
+      inreplace  "addons/CMakeLists.txt",
+        'add_subdirectory(Python)',
+        '#add_subdirectory(Python)'
+    end
     mkdir 'buildroot' do
       system "cmake", "..", *std_cmake_args
       system 'make'