Use yui-compressor (available in Debian / Ubuntu) instead of yuglify

The default Javascript / CSS compressor in django-pipeline is yuglify,
but that has to be installed via npm, which would drag in node as a
dependency - instead use the older yui-compressor which is available as
a Debian package.
There should be a trailing newline in the file
Remove the generated CSS, now being dealt with by pipeline
Move country-specific scss into each country's app
Refer to core SCSS imports with relative paths
Fix whitespace: remove a trailing empty line in a file
Use django-pipeline compressed and fingerprinted Javascript
Remove an unused {% load staticfiles %}
References to STATIC_GENERATION_NUMBER are no longer needed
Switch uses of STATIC_URL to the static template tag

This is so that the fingerprinted URLs will be used in production.