XHTML 5 snippet
Make md5_file fail when md5sum exits non-zero

Failure thanks to running md5sum outside of the pipe, combined with
set -e.
Add adaptive-wrap-mode

This is nice in visual-line-mode e.g. when editing Markdown bulleted
lists and such.
Add yaml-mode
Preserve indentation in org-mode code blocks

This got annoying when I had pasted some Python into one.
Convert some things from macros into functions

These never needed to be macros as far as I can see.  (Though maybe
I'm wrong about modifying keymaps?)