Fix login/signup issue

Issue was with the Catalyze API key, which needs “ios catalyze” in front of what I had. Now users can sign up and login. Users are segued to the main screen when this occurs.
Confirmed with Catalyze CEO that there is no data dashboard like there is on Parse—we’d have to create our own with the API. Will investigate this to try to confirm active users and record a test entry. From there, could use ACLs to restrict data access.
Refactor

Rename PCAViewController to PCALoginViewController
Add support for pain entering

Create symptom bit mask array of ints. Populate it with arbitrary values in a loop. Create cycleSymptoms method which uses switch to determine which method to call. Call painMethod in case 0 which creates and operates UI elements for pain recording. No action taken on submit (dependent on backend). Should consider moving painMethod and other methods to other classes if possible
Add multiple symptom screens

Significant changes. Reworked how symptom screens are shown. To avoid copy/paste code, only one method constructs these screens now. If we need screens without basic sliders, we’ll need another check on currentSymptom and an alternate method. Right now, it advances through all the symptoms and works pretty well at this point. Submit still does nothing—does not store data anywhere.

TODO:
NSAlert to confirm user entered value correctly before real submit action taken