Fix and improve specs related to bootstrapping

First and foremost fixes specs related to `Latex` and bootstrapping
the global `window.latex` instance.

spec/latex-spec.coffee

@@ -1,47 +1,52 @@
 helpers = require './spec-helpers'
 Latex = require '../lib/latex'
+{Opener} = require './stubs'
 
 describe "Latex", ->
-  [latex] = []
+  [latex, globalLatex] = []
 
   beforeEach ->
+    globalLatex = window.latex
+    delete window.latex
+
     latex = new Latex()
+    latex.initialize()
+
+  afterEach ->
+    window.latex = globalLatex
 
   describe "initialize", ->
     it "initializes all properties", ->
-      opener = helpers.nullOpener()
-      spyOn(latex, 'resolveOpenerImplementation').andReturn(opener.constructor)
-      latex.initialize()
+      spyOn(latex, 'resolveOpenerImplementation').andReturn(Opener)
 
       expect(latex.builder).toBeDefined()
       expect(latex.logger).toBeDefined()
       expect(latex.opener).toBeDefined()
 
   describe "setDefaultBuilder", ->
     it "sets the default builder to LatexmkBuilder", ->
-      origin = latex.builder
+      origin = latex.__builder
       latex.setDefaultBuilder()
 
       expect(origin).toBeUndefined()
       expect(latex.builder.constructor.name).toBe 'LatexmkBuilder'
 
   describe "setDefaultLogger", ->
     it "sets the default logger to ConsoleLogger", ->
-      origin = latex.logger
+      origin = latex.__logger
       latex.setDefaultLogger()
 
       expect(origin).toBeUndefined()
       expect(latex.logger.constructor.name).toBe 'ConsoleLogger'
 
   describe "setDefaultOpener", ->
     it "sets the default logger as resolved", ->
-      origin = latex.opener
-      opener = helpers.nullOpener()
-      spyOn(latex, 'resolveOpenerImplementation').andReturn(opener.constructor)
+      origin = latex.__opener
+      spyOn(latex, 'resolveOpenerImplementation').andReturn(Opener)
       latex.setDefaultOpener()
 
       expect(origin).toBeUndefined()
-      expect(latex.opener.constructor.name).toBe opener.constructor.name
+      expect(latex.opener.constructor.name).toBe Opener.name
 
   describe "Logger proxy", ->
     [logger] = []

spec/spec-bootstrap.coffee

@@ -1,11 +1,6 @@
 Latex = require '../lib/latex'
-Logger = require '../lib/logger'
-
-class NullLogger extends Logger
-  error: -> null
-  warning: -> null
-  info: -> null
+{Logger} = require './stubs'
 
 window.latex = new Latex()
 latex.initialize()
-latex.setLogger(new NullLogger())
+latex.setLogger(new Logger())

spec/spec-helpers.coffee

@@ -1,12 +1,8 @@
 require './spec-bootstrap'
+
 fs = require 'fs-plus'
 temp = require 'temp'
 wrench = require 'wrench'
-Opener = require '../lib/opener'
-
-class NullOpener extends Opener
-  open: (filePath, texPath, lineNumber, callback) -> null
-
 
 module.exports =
   cloneFixtures: ->
@@ -30,5 +26,3 @@ module.exports =
     originalInterval = env.defaultTimeoutInterval
     env.defaultTimeoutInterval = interval
     originalInterval
-
-  nullOpener: -> new NullOpener()

spec/stubs.coffee

@@ -0,0 +1,16 @@
+Logger = require '../lib/logger'
+Opener = require '../lib/opener'
+
+class NullLogger extends Logger
+  error: -> null
+  warning: -> null
+  info: -> null
+
+
+class NullOpener extends Opener
+  open: (filePath, texPath, lineNumber, callback) -> null
+
+
+module.exports =
+  Logger: NullLogger
+  Opener: NullOpener