create fix "strict" to introduce stricter syntax in fixes

[nicolasfranck]

Now the fixes like copy_field do not make a difference between

copy_field("field1","field2")

and

copy_field(field1,field2)

this makes it hard to introduce something like "literals".

Maybe add a fix like "strict" (or a better title), comparable to "use strict" from javascript?

[nics]

copy_field("009", "field2")
quoted numerals are the main cause of confusion