Bug fixes / Improvements.

Bug fixes

• Removed Pod folder from Example projects and updated to latest version.
• Reorganized main Xcode project.
• Prefixed Reachability class to avoid namespace clash.
• Removed a few assert statements in DropboxClientsManager to avoid hard crashes.
• Fixed deserialization bug where default field values for server response objects were assumed to be explicitly supplied by server.

Improvements

• Added ability to specify response queues for each route.