clarify framework vs. static library
closes #160 #164 #491: annotation layer sorting delegate method
remove v4 API support
Merge branch 'develop' into release
update changelog for 1.4.0
bump podspec version
tweak changelog for deprecations
bring back & properly deprecate marker sort properties
1.4.1 bumps
Merge branch 'release' of https://github.com/mapbox/mapbox-ios-sdk into develop