Merge pull request #3948 from minrk/sphinx-dir

Sphinx and PDF tweaks for nbconvert:

- add `--interaction=batchmode` to pdflatex call to avoid waiting for interactive input.

- use sphinx.package_dir to find texinputs directory regardless of on-disk location.

Closes  #3894.

IPython/nbconvert/post_processors/pdf.py

@@ -30,7 +30,7 b' class PDFPostProcessor(PostProcessorBase):'
         How many times pdflatex will be called.
         """)
 
-    command = List(["pdflatex", "{filename}"], config=True, help="""
+    command = List(["pdflatex", "--interaction=batchmode", "{filename}"], config=True, help="""
         Shell command used to compile PDF.""")
 
     verbose = Bool(False, config=True, help="""

IPython/nbconvert/transformers/sphinx.py

@@ -168,7 +168,7 b' class SphinxTransformer(Transformer):'
             resources["sphinx"]["header"] = self.use_headers
             
         # Find and pass in the path to the Sphinx dependencies.
-        resources["sphinx"]["texinputs"] = os.path.realpath(os.path.join(sphinx.__file__, "..", "texinputs"))
+        resources["sphinx"]["texinputs"] = os.path.realpath(os.path.join(sphinx.package_dir, "texinputs"))
         
         # Generate Pygments definitions for Latex 
         resources["sphinx"]["pygment_definitions"] = self._generate_pygments_latex_def()