Adds support for PDF417 barcode scanner

https://github.com/PDF417/pdf417-phonegap
Merge pull request #1 from documment/pdf417_scanner

approved
camera plugin constants now exported as $cordovaCameraConstants

The camera constants are used in the camera options. Without this
stubbed it was not possible to use the constants in code without errors.
The values used in the mock are directly copied from the source
of CordovaConstants.js that is added to a project when the
camera plugin is installed.
Adds setter for DATA_URL, FILE_URI or NATIVE_URI to cordova camera mock

The different image type values can be specified for the
DATA_URL, FILE_URI or NATIVE_URI types. This is helpful when smoke
testing an application in a browser
Adds rebuilt dist files