Remove old files that are no longer needed.

TODO

-* No need to pass the project path and podfile separately to UserProjectIntegrator.
-* Move Platform#xcodeproj to TargetDefinition#link_with.
-* Add multiple-platforms section to changelog.
-* Validate platforms for each target definition.
-* Validate that there are dependencies in a Podfile.
-* Validate that the dependencies in the targets don't conflict. E.g. two different versions of the same pod.
-* Move Podfile.lock generator from Installer into its own file.
-* Remove better_installer.rb file
-* One or more of the specs are changing the remote URL of the master repo in ~/.cocoapods

scratch-pad.md

-What I want it to do
---------------------
-
-
-Client
-------
-
-* Search libs
-
-* Install libs plus dependencies
-
-* Downloading of libs:
-  - As a git vendor
-  - Files (subset) from a git repo
-  - Should be implemented in such a way that people can add support for, for instance, svn
-
-* Automatically add files from lib manifest to Xcode project, but can be skipped
-
-* Calculate dependencies across a set of libraries like bundler
-
-* Wizard to create a manifest
-
-* Has git submodules which contain the actual manifests
-
-
-Manifest
---------
-
-* Is a runnable ruby file
-
-* Inherits from a base class that provides install strategies
-
-
-Other managers
---------------
-
-Kit: https://github.com/nkpart/kit
-
-1. Has to fork repos to change directory structure and add KitSpec
-2. Has good strategy for the way it add dependencies to the project
-3. Uses haskell, so does not have easy access to ways to manipulate plists (Xcode project) and leaves configuring of project up to user.
-4. Uses JSON for manifest. While simple, it does not allow for a way to adapt the build process to the repo (see #1)