custom categories, generic sections, launch pages

- Added cells for custom categories (which can be easily turned off at
compile-time)
- JSON data for resources is now a "resources" dictionary of section
names for keys, and arrays of categories for values
- there is also a "customResources" dictionary for user-added categories
- added first-launch splash page (incl. source asset) with instructions
- updated "launch" images to match look of first page
iPad support + better launch screen/buttons post-feedback

- added support for iPad
- received feedback on button layouts and first-launch instructions
iPad support + better launch screen/buttons post-feedback (part 2)

For some reason GitHub's native app didn't submit all my checked files
last time
TestFlight support + action items from Sam meeting

- added TestFlight support for beta testing
- Turn off custom categories for now (keep it simple)
- If selected photo has no GPS data, do not proceed.  Remind the user
to turn on Location Services.
- Map page: add fields displaying longitude/latitude
- Description page: add drop-down with Tanzania's administrative
regions, send as "region" field in JSON
point to new server, don't cover up notes when typing

- upload to new location in heroku
- description page: swap notes and region field to prevent keyboard
from hiding text
- added TestFlight checkpoints and logging
- fix usage of default region
- fix a slew of bugs related to adding/removing custom cells (custom
cells are still disabled btw)
project settings working with TestFlight