Updates to ios client

Storing credentials in the app, style tweaks, trying to make xcode do whitespace right, and some organization

Change-Id: I36c7c0f479dcd95c26c4dd53bacb8e5c6e66bc9f
Merge "Updates to ios client"
corpus: ignore exiftag rows for now

Change-Id: I5ccbb8517c8576bc0f554db73f2abd4b827b8388
search: add negative expressions and has:location

e.g. [is:image -has:location]

Change-Id: I03df0a1d5fea8394a33e3079d131224c116d4c0d