bug#19650: 25.0.50; python-shell-font-lock-post-command-hook breaks hippie-expand

[Carlos Pita]

hippie-expand sucessive completions depends on the marker
he-string-end having the same value the previous hippie-expand
invocation left it. But the delete-region call in
python-shell-font-lock-post-command-hook changes the value of that
marker after each hippie-expand invocation, so hippie-expand gets
stucked at the first candidate for ever.