PHP fatal destination is now a class parameter

wmerrors.ini had an hardcoded destination to a production server which
is not really nice for beta.  This patch makes the wmerrors.ini a
template accepting the 'fatal_log_file' variable, it is set as a default
parameter in applicationserver::config::php.  That will later on let us
set a different destination from the role classes.

Change-Id: I47ea00f92da9da38a4602f34d2649b39adab63ac