Pods Integration

Hello

In this pull request I've updated the project to work with cocoa pods. That includes being able to install the library as a pod as well as replacing the git-submodule of SLRemoting to using Podfile/podspec dependency. Below is a list of the changes.

Pods:
- Added Podfile for installing SLRemoting dependency when you need to compile/build the project. This currently points to the fork I made of SLRemoting and should be changed to `pod 'SLRemoting', '~>1.0.1'` when the podspec for SLRemoting has been added to the cocoapods podspec repo.
- Added podspec for pods installation integration - The dependency flag for SLRemoting will not work until SLRemoting podspec has been added to the cocoapods podspec repo
- Changed other linker flags to being `$(inherited) to inherit from pods config (Pods config contains -ObjC which was the only linker flag there before
- Changed to Standard Architectures - This one I wasn't too sure about. The configuration you guys had before was causing warnings to be thrown with duplicate architectures. Is there a particular reason the project wasn't just using standard architectures before?

 
This pull request corresponds with the pull request I submitted for SLRemoting: https://github.com/strongloop/strong-remoting-ios/pull/3