CocoaPods usage updates

Per recommendations I'm reading and discovering:
• Removed Pods directory, and ignoring in the gitignore.
• Leaving Podfile.lock in.
• Added P-001.xcworkspace and unignored “*.xcworkspace” pattern when root-level (apparently still a bad idea when a sub-dir of an xcodeproj).

Also:
• Changed the FontAwesomeIconFactory version requirement from `'>= 1.0.1', '< 2.0'` to `'~> 1.0'` in order to avoid a CocoaPods bug.
• Updated the version of FontAwesomeIconFactory to 1.1 and CocoaPods itself to 0.20.2 in the process.
• Put basic build instructions in the README.