Default to post author if post editor is missing

Fixes #100
Use customizable deleted-user structure
Enforce string value for display_name
Add missing ')'

Staged only part of a change -- stupid mistake.
Deleted-user variable is not risky
Merge branch 'master' into issue-100
Merge branch 'master' into issue-100
Fix byte-compile warnings

Fixes #115
Remove need-auth from sx-request--build-keyword-arguments
Autload sx-tab-frontpage

Affects #109
Autoload sx-tab-frontpage
Autoload sx-tab-frontpage correctly
Merge pull request #119 from vermiculus/buttons

Buttons
Merge pull request #118 from vermiculus/compilation-issues

 Compilation issues
Merge pull request #120 from vermiculus/reorganize-question-mode

Reorganize question mode
Merge branch 'master' into issue-100

Conflicts:
	sx-question-mode.el
Fix #57. Set the buffer as unibyte then multibyte again.
Merge pull request #125 from vermiculus/issue-57-unibyte-vs-multibyte

Fix #57. Set the buffer as unibyte then multibyte again.
Define and use sx-question-mode-display-buffer-function
Make sx--data-here throw error on failure.