a2_methodSignaturesCompatible only checks first character now.
Merge pull request #146 from OliverLetterer/modern-runtime-blocks

a2_methodSignaturesCompatible only checks first character now.
Fixes libffi reference in Xcode project.
Fixes libffi header reference for iOS.
Renames targets to follow convention. Closes #147.
Fixes shadowed variables warning. Closes #150.
Update project settings
Remove unused framework references