Use option to remove migrations on uninstall

Running the migrations trashes any data in the new columns and tables,
so if you're only upgrading the theme you don't want this to happen. Run
the migrations by setting the 'REMOVE_MIGRATIONS' env var.
Point link at section describing what a request must contain
Justify the help text.
Minor text changes.
Merge branch 'uninstall_migrations'
Merge branch 'move-public-law-link'
Merge branch 'justify-help'
Minor text changes.
Text changes as requested by email
Text change as requested by email
Merge branch 'text-changes'