Add .nojekyll file and implemented 'upload' build rule.

Makefile:
- Copy .nojekyll file to html directory so github will serve content
  from directories with names having leading underscores.
- 'upload' build rule runs ghp-import, merges into master, and pushes
  all branches to origin.

Author: tboggs

Makefile

@@ -40,9 +40,12 @@ git-submodules:
 
 site:		images sphinx-html
 	cp static/CNAME sphinx/_build/html
+	cp static/.nojekyll sphinx/_build/html
 
 upload:
-	@echo "Not yet implemented."
+	ghp-import sphinx/_build/html/ && \
+	git checkout master && git merge gh-pages -m "gh-pages merge" && \
+	git push origin --all && git checkout source
 
 clean:
 	$(MAKE) -C $(SPHINXDIR) clean

static/.nojekyll

@@ -0,0 +1,2 @@
+# This file is present so that github will serve file from directories
+# having names with a leading underscore.