Add sami configuration file.

build/sami.conf.php

@@ -0,0 +1,31 @@
+<?php
+
+// Prevent e.g. 'Notice: Constant MATH_BIGINTEGER_MONTGOMERY already defined'.
+class MyArrayStore extends Sami\Store\ArrayStore
+{
+    public function removeClass(Sami\Project $project, $name)
+    {
+        unset($this->classes[$name]);
+    }
+}
+
+$iterator = Symfony\Component\Finder\Finder::create()
+    ->files()
+    ->name('*.php')
+    ->in(__DIR__ . '/../phpseclib/')
+;
+
+$versions = Sami\Version\GitVersionCollection::create(__DIR__ . '/../')
+    ->add('master')
+    ->add('php5')
+;
+
+return new Sami\Sami($iterator, array(
+    'theme'                => 'enhanced',
+    'versions'             => $versions,
+    'title'                => 'phpseclib API Documentation',
+    'build_dir'            => __DIR__.'/api/output/%version%',
+    'cache_dir'            => __DIR__.'/api/cache/%version%',
+    'default_opened_level' => 2,
+    'store'                => new MyArrayStore,
+));