Theming / functionality broken after 5.70

After we upgraded a client it seems that Availability stopped working. It was expecting a few things that no longer existed in the Contact form so I reworked the code a bit.

Related issues

• addStyleFile is too late in the header and was complaining about missing CRM.availability... functions
• README provides an example, but actually the CRM.availabilityWidgetEdit requires an ID, which when not included was causing errors
• Theming issues like centering
• Generation of clickable table in CRM.availabiltyWidgetEdit stopped working