Typealias for keychain query dictionary; Removed duplicated `keychainQuery` function implementation; Removed `String` cast when working with keychain query dicionaries; Removed unecessary cast to `AnyObject?` for some keychain query dictionary values; Added `@discardableResult` for some functions to remove warnings
Typealias for keychain query dictionary; Removed duplicated `keychainQuery` function implementation; Removed `String` cast when working with keychain query dicionaries; Removed unecessary cast to `AnyObject?` for some keychain query dictionary values; Added `@discardableResult` for some functions to remove warnings

Bunn/macGist,Bunn/macGist