moved options parsing into separate file and created test

moved the options paring system into it's own function so that it may be testable

lib/proto/parse-options.js

@@ -0,0 +1,35 @@
+module.exports = function parseOptions(options){
+  this.options = options
+  this.options.elements = this.options.elements || "a[href], form[action]"
+  this.options.selectors = this.options.selectors || ["title", ".js-Pjax"]
+  this.options.switches = this.options.switches || {}
+  this.options.switchesOptions = this.options.switchesOptions || {}
+  this.options.history = this.options.history || true
+  this.options.analytics = this.options.analytics || function(options) {
+    // options.backward or options.foward can be true or undefined
+    // by default, we do track back/foward hit
+    // https://productforums.google.com/forum/#!topic/analytics/WVwMDjLhXYk
+    if (window._gaq) {
+      _gaq.push(["_trackPageview"])
+    }
+    if (window.ga) {
+      ga("send", "pageview", {page: options.url, title: options.title})
+    }
+  }
+  this.options.scrollTo = (typeof this.options.scrollTo === 'undefined') ? 0 : this.options.scrollTo;
+  this.options.debug = this.options.debug || false
+
+  // we can’t replace body.outerHTML or head.outerHTML
+  // it create a bug where new body or new head are created in the dom
+  // if you set head.outerHTML, a new body tag is appended, so the dom get 2 body
+  // & it break the switchFallback which replace head & body
+  if (!this.options.switches.head) {
+    this.options.switches.head = this.switchElementsAlt
+  }
+  if (!this.options.switches.body) {
+    this.options.switches.body = this.switchElementsAlt
+  }
+  if (typeof options.analytics !== "function") {
+    options.analytics = function() {}
+  }
+}