New pathhistory setting for the history database directory

[Julien ÉLIE]

About it, the default pathhistory value for new installations remains 
pathdb in the shipped inn.conf file.  It can be set at configure time 
with the --with-history-dir option, or manually changed after the 
installation.

I think it is fine to keep the history database in its legacy directory. 
  One has to elaborate a special configuration to benefit from having a 
separate directory for it.
If someone believes it would be better to ship <prefix>/history by 
default instead of <prefix>/db in the sample inn.conf file, do not 
hesitate to tell.

-- 
Julien ÉLIE

« – Ce serait une joyeuse idée de faire une tempête dans nos cerveaux,
     n'est-il pas ?
   – Il veut parler d'une réunion de travail ! » (Astérix)