Install elpy for python

This also requires:

    pip install elpy
    pip install jedi

See https://github.com/jorgenschaefer/elpy/wiki

I've disabled elpy's use of flymake (because I already use flycheck
instead, with a fair bit of customisation) and autocomplete (because the
popup box is annoying; I still need to hook in elpy's completion
suggestions to my <TAB> completions).
Split windows horizontally if frame is wide enough
Document how to generate the Info "directory" file
Enable page-break-lines-mode in programming mode buffers

Requires my change (now merged upstream):
https://github.com/purcell/page-break-lines/commit/4285943d
Revert "Install elpy for python"

This reverts commit cefa9e9e2fcc775233c7277188e51727e836253e.

I want to see if this is what's screwing up my `M-q'.
confluence-mode to edit YouView wiki pages directly

"Confluence" is a wiki made by Atlassian.

Use `confluence-get-page'; saving the buffer normally will push the
changes.
Run flycheck on python files in my stb-tester project
magit: Use 8 digits (instead of 7) for abbreviated git SHAs

This matches my ~/.gitconfig setting of "core.abbrev = 8".