Highlight schema creation more, with more explicit call to run.

Fixes #647.
Remove deprecated parameters from _config.yml.
Add warning about micro instances.

Fixes #654.
add changing_colours example to customising
switch from Maruku to kramdown

This avoids the warnings about to_s that maruku spits out.
kramdown is another markdown plugin supported by Jekyll (and
importantly github pages).
Split up customising section into more pages.

Treat the colours CSS tutorial as a general CSS introduction;
consolidate and add more documentation on geocoder, languages,
Transifex, templates, etc.
Merge remote-tracking branch 'origin/gh-pages' into issues/599-gh-pages-redesign

Conflicts:
	customising/fms_and_mapit.md
	stylesheets/styles.css
Sidebar heading/links, and breadcrumbs.