Fixed improper variables definition in header file
Some header were creating variable, this is a bad practice which
is likely to not behave as expected. This creates one distinct
variable in each object file that used the header, and:
- on well behaved compiler, this ends up in a link error (see
commit
39fdb451ba6ff84430507e327fa01a43f40b7315 for an example)
- on bad behaving compiler, this can be linked as multiple local
variable, thus having strange effects when running program
- on insouciant compiler (who said gcc?) the variables are
silently merged, hiding portability issues