[FIX] Avoid error "The record has been modified, your changes will be discarded"

[alexis-via]

Avoid error "The record has been modified, your changes will be discarded. Are you sure you want to leave this page ?"

@luc-demeyer This is the bug you were looking for...

[rafaelbn]

:+1

[luc-demeyer]

@alexis-via
I was just about to make the exact same PR but you took me in speed.
The widget="char" on an integer works ok in 8.0 but not in 10.0.
This PR brings us back to the 'ugly' view where the year 2018 is presented with a dot after the 2 -> 2.018.

We could work around it by turning this field into a real char field but we may break some localisation modules.

I propose that we take this approach in the 11.0 port.

@rvalyi
Do you agree to modify #47 like that ?

[alexis-via]

I'm OK to modify this field to char in v11.