Fix 'make distcheck' and add lost document template

doc/Makefile.am

@@ -1,7 +1,7 @@
 EXTRA_DIST = _static _templates conf.py \
     index.rst introduction.rst installation.rst \
     configuration.rst sample_rulebase.rst internals.rst \
-    contacts.rst changes.rst \
+    contacts.rst changes.rst libraryapi.rst \
     lognormalizer.rst license.rst graph.png
 
 htmldir = $(docdir)
@@ -13,13 +13,13 @@ built_html = _build/html
 #
 
 # You can set these variables from the command line.
-SPHINXOPTS    =
+SPHINXOPTS    = -n -W -c $(srcdir)
 #SPHINXBUILD   = sphinx-build
 PAPER         =
 BUILDDIR      = _build
 
 # Internal variables.
-ALLSPHINXOPTS   = -d $(BUILDDIR)/doctrees $(SPHINXOPTS) .
+ALLSPHINXOPTS   = -d $(BUILDDIR)/doctrees $(SPHINXOPTS) $(srcdir)
 
 .PHONY: clean-local html-local man-local all-local dist-hook install-data-hook