readme update

Updated readme

Updated readme: explain how to use it in older Delphi versions.

Reverted FRAMEWORK_FMX compile directive and fixed some QR test images.

Updated demo files.

Readme

Updated fix for compatability with Delphi 10.2 version: #143

Updated readme

fix: Overflow on Android when overflow check is off. Related to: #123

fix: when using TBarcodeFormat.Auto certain QRCodes causes integer ov…

…erflow in EAN parser. #133