Fix Python 3 issues in REST code. * Need to use .get not .getheader for HTTP headers (see hg commit fec18298ae02, "Python 3 preparation: HTTP headers handling in roundup_server.py."). * Need to use key not cmp with sort (see hg commit 3fa026621f69, "Python 3 preparation: comparisons."). * dispatch output must be bytes, not str, otherwise writing it to the socket (e.g. in roundup-server) will fail. This fixes issues shown up attempting to access the REST interface with a browser with Python 3 (as opposed to with the Roundup testsuite, which also has known REST issues with Python 3).

recursive-include share *
recursive-include roundup *.*
recursive-include frontends *.*
recursive-include scripts *.* *-*
recursive-include tools *.* base64
recursive-include test *.py *.txt
recursive-include doc *.html *.png *.txt *.css *.example
recursive-include detectors *.py README.txt
global-exclude *.pyc *.pyo .DS_Store *.orig *.rej *~ \#*
include run_tests.py demo.py *.txt
include doc/conf.py doc/roundup-favicon.ico
exclude doc/security.txt
include locale/*.po locale/*.mo locale/roundup.pot