Finally dealt with the vformatter() thing that's been sitting in STATUS

since october.

- apapi_vformatter() is generic printf-style routine with arbitrary
  output
- replaces ap_snprintf(), eliminate the possibility of HAVE_SNPRINTF
- replaces bprintf() and bvprintf()
- add new psprintf()/pvsprintf() which allocate the string from the
  pool -- no static limitations
- use psprintf() in a bunch of places


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@80715 13f79535-47bb-0310-9956-ffa450edef68