Localise schedule times

Show local times on schedule and presentation details
if user is in a different timezone to the conference.

Fix schedule edit

Use main base template instead of intermediate base.
Remove references to Bootstrap 3 and update to Bootstrap 4.
Add edit button to standard grid/mobile view instead of duplicating.

Remove reference to analytics.html

Don't know what it was, but it currently doesn't exist.

Asset cleanup

Remove in-app stale resources and their branching of different cons.
Remove dist and move everyting into static/src.
Remove unused stale resouces such as less and hbs, etc.

Minimum viable changes to get schedule to display (#64)