ikiwiki/ news/ version 3.20180228

ikiwiki 3.20180228 released with these changes

- core: Don't send relative redirect URLs when behind a reverse proxy
- core: Escape backticks etc. in directive error messages as HTML entities so that the error message is not subsequently parsed as Markdown
- mdwn: Enable fenced code blocks, PHP Markdown Extra-style definition lists and GitHub-style extensions to HTML tag syntax when used with Discount >= 2.2.0 (Closes: #888055)
- img: Fix auto-detection of image format (if enabled, which is strongly discouraged) with ImageMagick >= 6.9.8-3
- rst: Use Python 3 instead of Python 2
- build: `set -e` before each `for` loop, so that errors are reliably trapped
- build: Use if/then instead of `||` so that the `-e` flag works
- build: Ensure that pm_to_blib finishes before rewriting shebang lines
- t: Make the img test pass with ImageMagick >= 6.9.8-3 (Closes: #891647)
- debian: Remove unused Lintian overrides for duplicate word false positives
- debian: Declare compliance with Debian Policy 4.1.3