title: Kivy app crashes after being packaged with pyinstaller due to window issue
body: <p>I'm trying to package my kivy project with Pyinstaller but it crashes and spits this out </p>
  
  <pre><code>[CRITICAL          ] [Window      ] Unable to find any valuable Window     provider at all!
  sdl2 - Exception: SDL2: Unable to load image
   File "site-packages\kivy\core\__init__.py", line 67, in core_select_lib
   File "site-packages\kivy\core\window\window_sdl2.py", line 138, in __init__
   File "site-packages\kivy\core\window\__init__.py", line 722, in __init__
   File "site-packages\kivy\core\window\window_sdl2.py", line 255, in   
   create_window
  
   File "site-packages\kivy\core\window\__init__.py", line 897, in create_window
   File "kivy\graphics\instructions.pyx", line 756, in     
   kivy.graphics.instructions.RenderContext.__init__ (kivy\graphics\instructions.c:10729)
   File "site-packages\kivy\core\image\__init__.py", line 512, in __init__
   File "site-packages\kivy\core\image\__init__.py", line 700, in _set_filename
   File "site-packages\kivy\core\image\__init__.py", line 430, in load
   File "site-packages\kivy\core\image\__init__.py", line 198, in __init__
   File "site-packages\kivy\core\image\img_sdl2.py", line 42, in load
  
  [INFO              ] [Audio       ] Providers: audio_sdl2 (audio_ffpyplayer ignored)
  [CRITICAL          ] [App         ] Unable to get a Window, abort.
  Exception ignored in: 'kivy.properties.dpi2px'
  Traceback (most recent call last):
  File "site-packages\kivy\utils.py", line 513, in __get__
  File "site-packages\kivy\metrics.py", line 175, in dpi
  File "site-packages\kivy\base.py", line 126, in ensure_window
  SystemExit: 1
  [CRITICAL          ] [App         ] Unable to get a Window, abort.
  Exception ignored in: 'kivy.properties.dpi2px'
  Traceback (most recent call last):
  File "site-packages\kivy\utils.py", line 513, in __get__
  File "site-packages\kivy\metrics.py", line 175, in dpi
  File "site-packages\kivy\base.py", line 126, in ensure_window
  SystemExit: 1
  [CRITICAL          ] [App         ] Unable to get a Window, abort.
  </code></pre>
  
  <p>I did not create my own spec file I chose to do it via the command line by passing the required arguments any suggestions?</p>
  
  <p>This is the spec file generated by pyinstaller</p>
  
  <pre><code># -*- mode: python -*-
  
  block_cipher = None
  
  
  a = Analysis(['apv.py'],
           pathex=['C:\\Python34\\Lib\\site-packages\\kivy', 'C:\\Python34', 'C:\\Python34\\Lib', 'C:\\Python34\\Lib\\site-packages', 'C:\\Users\\suroh\\Desktop\\my-python-modules', 'C:\\Python34\\Lib\\site-packages\\kivy\\deps', 'C:\\Python34\\Lib\\site-packages\\kivy\\graphic', 'C:\\Python34\\DLLs', 'C:\\Python34\\libs', 'C:\\Python34\\Scripts', 'C:\\Python34\\share\\sdl2\\bin', 'C:\\Python34\\share\\glew\\bin', 'C:\\Python34\\share', 'C:\\Python34\\Tools', 'C:\\Python34\\Lib\\ctypes', 'C:\\Python34\\Lib\\distutils', 'C:\\Users\\suroh\\Desktop\\Python Projects\\testp\\Beta 01'],
           binaries=None,
           datas=None,
           hiddenimports=[],
           hookspath=[],
           runtime_hooks=[],
           excludes=['pygame'],
           win_no_prefer_redirects=False,
           win_private_assemblies=False,
           cipher=block_cipher)
  pyz = PYZ(a.pure, a.zipped_data,
           cipher=block_cipher)
  exe = EXE(pyz,
        a.scripts,
        exclude_binaries=True,
        name='apv',
        debug=False,
        strip=False,
        upx=True,
        console=False , icon='LauncherIcon.ico')
  coll = COLLECT(exe,
             a.binaries,
             a.zipfiles,
             a.datas,
             strip=False,
             upx=True,
             name='apv')
  </code></pre>