Patch for reloading service files

[Havoc Pennington]

Hi,

Yep, should avoid unistd.h and stdio.h outside of dbus-sysdeps.c, adding
to dbus-sysdeps.c as required. This is both a portability thing and an
audit thing (easily see all dependencies on C library, and force use of
DBusString/DBusError). Exception, inside DBUS_BUILD_TESTS stdio is fine.

- entry == 0 should be entry == NULL
- any way we can get out of storing the full path for each entry?
  seems sort of memory intensive
- declaration/assignment mixing

Oops:
 -  _dbus_string_init_const (&dir, directory);
 +  //_dbus_string_init_const (&dir, directory);

- how slow is it to run the unit test with _dbus_test_oom_handling?
  maybe there are few enough allocs in this that it's manageable.
  You should at least have code to run this test and run it once, 
  then #ifdef it out ;-)

For your next trick, how about dynamically reloading the config file?
;-)

Thanks,
Havoc