Migrate existing production site data to new formats

[chrismclarke]

During latest dev a number of changes were made to user profile and howTo data structures. HowTos aren't a big issue as they are using a different database endpoint and so prior data just won't show (instead of throwing errors), but would still be good to have migrated for release.

Additionally user profiles will need to be migrated. This might be more tricky as the original user accounts may not have picked a username, so will need to figure out best strategy to get updated registrations

[chrismclarke]

if this hasn't already been done then it can be merged into #539
closing