Front-end - Availability editor

[deltabrot]

To set availability, there are two input fields to set the start and end times, you are then able to define zero or more breaks.

Tapping the breaks input field should show a pop-up start and end time editor and then "Add" the break, you can do this multiple times and it should show a list of added breaks somewhere near/inside the input field.

Then the user will tap dates on the calendar, they can tap one or more dates which will be "primed" to be given the defined schedule above.

Finally the user will tap "Save", at which point all chosen dates will have the defined schedule applied and stored in the database.

There should be some form of visual indicator to show which dates are in the past, which dates already have a set schedule.

Consideration needs to be put into editing an existing schedule, or deleting one.

Issue dependencies:
#42 #43 #44