InsightToolkit (itk) 4.2.0

Closes Homebrew/homebrew#14981.

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

Formula/insighttoolkit.rb

@@ -0,0 +1,27 @@
+require 'formula'
+
+class Insighttoolkit < Formula
+  homepage 'http://www.itk.org'
+  url 'http://sourceforge.net/projects/itk/files/itk/4.2/InsightToolkit-4.2.0.tar.gz'
+  sha1 '5d1fb109cc8b8648772b654f898a531d9af01e38'
+
+  head 'git://itk.org/ITK.git'
+
+  option 'examples', 'Compile and install various examples'
+
+  depends_on 'cmake' => :build
+
+  def install
+    args = std_cmake_args + %W[
+      -DBUILD_TESTING=OFF
+      -DBUILD_SHARED_LIBS=ON
+    ]
+    args << ".."
+    args << '-DBUILD_EXAMPLES=' + ((build.include? 'examples') ? 'ON' : 'OFF')
+
+    mkdir 'itk-build' do
+      system "cmake", *args
+      system "make install"
+    end
+  end
+end