avoid isnan() for pre-iOS 6 deployment
bump FMDB to 2.3 & simplify header imports
fixes #308: handle dispatch queues properly with ARC on iOS 6+
use SSL for all mapbox.com connections
fixes #468: support v4 + access tokens
add docs for access token
update FMDB header search path
first cut of podspec rename
bump FMDB in podspec to complement c2b625b59bff3a28e14fba76833b2f8ba547a003
HTTPS website & social media URL in podspec
update podspec to point to tag per https://github.com/mapbox/Fingertips/commit/72cab4ec28e7ffec7443beac7da4300aeda7055c#commitcomment-7158506
fixes #474: update library path
fixes #475: avoid verbose logging for empty tile queries
Merge branch 'develop' of https://github.com/mapbox/mapbox-ios-sdk into develop