Update .env-example files to split into dev/prod.

Split these like we've done with Forward Works because there are some crucial different values in the prod one (e.g. SYSTEM_EMAIL, which is changing in this ticket).  Should be easier to track these now.
Removed end date and time from incident emails.
Update to new tfc.govt.nz domain.
Move handlebars helper into new sub-directory.
Remove seconds from time display.
Change wording and field order.
Close unclosed <br /> tags.
Merge pull request #8 from mediasuitenz/update/incident_emails#TMP-323

Update/incident emails#tmp 323