Another improvement makes to the Image-downloader code.
- Introduced function “Inputchecker” to validate user input
- vaguely match the strings user inputs and try to match with the strings, if not match ask the user to re-type the number
- precisely matching the version number user input using regex
- separately handling onefs and insightiq image name and url path
- get the list of filename from URL path and dump to help the user choose insightiq version to download