Added example iOS program.
Implemented improved error handling for deleteFile

- Removed unimplemented progress bar methods.
Updated to reflect peer review.

- Changed README.md example code to not use inline functions for plugin function
  callbacks.

- Updated example index.html to not use nested inline functions.  One level of
  inline functions is used in some places but nested inline functions should no
  longer currently be in use for this example.
Updated README with comment about error handling.
Updated the example to include cordova framework.
Merge pull request #1 from wcwynn/updates-for-1.9

Added example iOS program.