Add PDF compatible HTML helper wrappers.

The rails helpers like number_with_precision do escape some characters we
do want to directly use in PDF. This unescapes them again.
Update rails and related gems.
Updat simple_form and haml gems.
Update i18n_rails_helpers gem.
Fix balance and profit sheet.
Fix dangling dash in balance and profit sheet titles.
Update has_accounts and _engine gems.