firebase-ios-sdk

Copy component container to GoogleUtilitiesComponents (#4113)

* Move component container to GoogleUtilities.

This will allow non-Firebase SDKs to take advantage of the component
system. Note: Firebase Core will eventually move over to use this, but
more investigation is needed about how this can be done with the least
amount of churn for other SDKs.

* Fix dependency on Logger.

* Add CHANGELOG entry.

* Fix selector name.

* Move ComponentContainer subspec to new pod.

* Rename to GoogleUtilitiesComponents.

* Style, make public headers.

* Update travis with new name.

* Add project to if_changed.sh

* Review comments.

* Enabled static framework, changed homepage.

* Fix missing quote.