Create and view performances

This feature turned out to be several:
*Create a performance
*View a performance
*View the date create and by whom
*Add multiple customers and multiple partners to a performance
*View all customers and partners associated with a performance
*View a list of all performances by customer

@amZotti, @MikeyMurph77 - please take a look
word. i'd prefer ```primary_owner``` or ```owner``` even if you display it as ```prime``` on the form, just because other programmers you work with might not know that and the word prime has a few meanings. but that might not be necessary