Introduced allowZero to control if zero values should be cleared when…

[ToreOlavKristiansen]

… clearOnEmpty is true

This fixes the case where you want to allow empty and '0' as input field values. '0' is no longer considered empty if you raise the allowZero flag.

[ToreOlavKristiansen]

The codacy review failed, but I did change anything that causes it to.

[freitasmurillo]

@ToreOlavKristiansen you've added the control variable allowZero to the line where Codacy found some issues. This issues already were there but as you change the code line the tools is allowed to scan this particularly stretch of code.

If you could please fix only these 3 errors related to the lines you changed. You must no pay attention to others errors.

Thank you

[ToreOlavKristiansen]

@freitasmurillo Done :)