App extension back to Mixpanel.podspec + misc fixes
- No longer have two separate podspecs for iOS apps and app extensions #715
- Fix mini in app positioning on iphone X #731
- Fix a UIControl not on main thread bug (thanks @michalcichon) #733
- Make it so
alias
implicitly callsidentify
as that's almost required and which identifier to callidentify
with afteralias
is confusing #730