make iproj now produces a target that pulls together static libraries like core and platform-ios into a real dynamic framework. iosapp is pretty much just a regular iOS application that links Mapbox.framework (except for the inclusion of default_styles.hpp). iosapp runs fine in the Simulator and on a device, and the same is true for any application linking against Mapbox.framework.
The ipackage target produces both a Bitcode-disabled static framework and a Bitcode-enabled dynamic framework, eliminating the need for a separate framework.sh. It disables code signing, since that happens on copy when the framework is embedded inside the application bundle. It also merges the device and simulator builds into a single fat framework.
Also bumped itest minimum deployment target to iOS 8.0, the first version that supports linking frameworks.
Fixes#828.
this will make it easier to add more targets to iOS builds in the future. It'll also help by having Xcode files named after the platform they're for, so it's easier to distinguish windows
