MOBSDK-673: Move existing build scripts into "scripts" subdirectory
MOBSDK-673: New build scripts
- Removed embedded lipo script from pxbproj file
- common.sh: Sets common build variables and utility functions
- build_framework.sh: Builds the SDK as a framework in either Release (default) or Debug configuration
- build_appledoc.sh: Builds documentation in docset format using appledoc
- build_package.sh: Builds framework and optionally documentation. Suppress documentation with "--no-docs"
- run_unit_tests.sh updated to use new common script.
Merge pull request #230 from mikeh/master

MOBSDK-673 Refactor SDK deliverable to framework structure & cleanup build scripts