Added a new API method getPadID for reversing the Readonly ID and introduced the API level 1.4.1. Based on: https://github.com/disy-mk/etherpad-lite/commit/97402f60b89549b32238505397c781dce8d79a4c
Implemented the the new API method getPadID for reversing the Readonly ID. Based on: https://github.com/disy-mk/etherpad-lite/commit/ff88c19fc12887a49fdb752adb15ee3145f521f0
Enhanced the Example for the API Method getPadID and make the return value consistent to other functions
Renamed the variable to prevent possible problems.
Corrected the API Version number.
Merge pull request #2165 from stephan48/develop

Added an API method for retrieving the padID from the readonlyID