docs/pyboard: For latex build, use smaller quickref jpg, and no gifs.

The latexpdf target needs images that fit on the page, and does not support
gifs.

docs/pyboard/quickref.rst

@@ -9,10 +9,17 @@ other versions of the pyboard:
 or `PYBLITEv1.0-AC <http://micropython.org/resources/pyblitev10ac-pinout.jpg>`__
 or `PYBLITEv1.0 <http://micropython.org/resources/pyblitev10-pinout.jpg>`__.
 
+.. only:: not latex
+
    .. image:: http://micropython.org/resources/pybv10-pinout.jpg
       :alt: PYBv1.0 pinout
       :width: 700px
 
+.. only:: latex
+
+   .. image:: http://micropython.org/resources/pybv10-pinout-800px.jpg
+      :alt: PYBv1.0 pinout
+
 General board control
 ---------------------
 

docs/pyboard/tutorial/fading_led.rst

@@ -3,6 +3,8 @@ Fading LEDs
 
 In addition to turning LEDs on and off, it is also possible to control the brightness of an LED using `Pulse-Width Modulation (PWM) <http://en.wikipedia.org/wiki/Pulse-width_modulation>`_, a common technique for obtaining variable output from a digital pin. This allows us to fade an LED:
 
+.. only:: not latex
+
    .. image:: http://upload.wikimedia.org/wikipedia/commons/a/a9/Fade.gif
 
 Components