Fix string/bytes issues under python 3. 1) cgi/client.py: override cgi.FieldStorage's make_file so that file is always created in binary/byte mode. This means that json (and xml) are bytes not strings. 2) rest.py: try harder to find dicttoxml in roundup directory or on sys.path. This just worked under python 2 but python 3 only searches sys.path by default and does not search relative like python 2. 3) rest.py: replace headers.getheader call removed from python 3 with equivalent code. 4) rest.py: make value returned from dispatch into bytes not string. 5) test/caseinsensitivedict.py, test/test_CaseInsensitiveDict.py: get code from stackoverflow that implements a case insensitive key dict. So dict['foo'], dict['Foo'] are the same entry. Used for looking up headers in mocked http rewuset header array. 6) test/rest_common.py: rework tests for etags and rest to properly supply bytes to the called routines. Calls to s2b and b2s and use of BytesIO and overriding make_file in cgi.FieldStorage to try to make sure it works under python 3.

TMP  := _tmp
HTML := html

.PHONY: help clean html linkcheck

help:
	@echo "Please use \`make <target>' where <target> is one of"
	@echo "  html      to make standalone HTML files"
	@echo "  linkcheck to check all external links for integrity"

clean:
	-rm -rf $(TMP) $(HTML) docs COPYING.txt

docs:
	ln -s ../../doc ./docs
	ln -s ../../COPYING.txt

html: docs
	mkdir -p $(TMP)/doctrees $(HTML)
	sphinx-build -b html -d $(TMP)/doctrees . $(HTML)

linkcheck:
	mkdir -p $(TMP)/linkcheck $(TMP)/doctrees
	sphinx-build -b linkcheck -d $(TMP)/doctrees . $(TMP)/linkcheck
	@echo
	@echo "Link check complete; look for any errors in the above output " \
	      "or in .build/linkcheck/output.txt."