Adds pod spec cat subcommand

The command searches for the specfile and prints the most
recent version onto standard out.

http://superuser.com/questions/259703/get-mac-tar-to-stop-putting-filenames-in-tar-archives

* add_podfile:
  [Project] Use the relative path for the Podfile.
  [Project] Add the Podfile to the Pods project.

Conflicts:
	lib/cocoapods/project.rb
	spec/unit/project_spec.rb

* DirList:
  [DirList] Support for excluded patterns
  [LocalPod] Added DirList class.
  [Git] UI improvements.
  [Installer] Show project genration step.

Conflicts:
	lib/cocoapods/local_pod.rb

* master:
  Release 0.15.2
  [Bundle] Update.
  [Gemspec] Require Xcodeproj 0.3.5.
  Remove stray puts.
  Update the lockfiles of the examples.
  [Gemfile] Install and remove dependency on letters gem.
  [LocalPod] Always use Pathname::glob.
  [Gemspec] Use spermy indicator for xcodeproj.
  [Specs] Complete revert of 8e72cbe1
  Fixed a bug with the flags passed into `Dir.glob`
  Fixing a bug where `downcase` was being called on the list of used file paths
  Updated `clean_paths` and `expand_paths` methods to use `File::FNM_CASEFOLD`
  [Linter/Push] Properly singularize words in output.
  [Bundler] Update.
  [UI] Support for running CocoaPods without a terminal.
  [Git] Force a barebone repo for the cache.
  [Git] Code clean up.
  [LocalPod] Fixing clean paths

Conflicts:
	lib/cocoapods/local_pod.rb