In ra_serf verify if incoming integers are really integers. Before this patch
we would just assume these values were 0 if they weren't valid.

* subversion/libsvn_ra_serf/blame.c
  (blame_opened):
* subversion/libsvn_ra_serf/getlocations.c
  (getloc_closed):
* subversion/libsvn_ra_serf/getlocationsegments.c
  (gls_closed):
* subversion/libsvn_ra_serf/get_deleted_rev.c
  (getdrev_closed):
* subversion/libsvn_ra_serf/log.c
  (collect_path,
   log_closed):
* subversion/libsvn_ra_serf/merge.c
  (merge_closed):
* subversion/libsvn_ra_serf/stat.c
  (dirent_walker): Check integer value for validity.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1557709 13f79535-47bb-0310-9956-ffa450edef68