Add CocoaPods setup to READMEs

Fixes GH-57
Fix compilation errors with iOS 5 SDK

Remove literal dict key set/lookup syntax and wrap BOOL literals in parens
Add Travis CI support
Merge pull request #58 from gcurtis/travis

Add Travis CI support
Add Travis CI badges to readmes
Merge pull request #59 from gcurtis/travis-badge

Add Travis CI badges to readmes
Add note to readmes about storing refresh tokens

Fixes GH-61.