Update to 1.4.38
----------------------
- 1.4.38 - 2015-12-05
  * [stat-cache] fix handling of collisions, might have returned wrong
    data (fixes #2669)
  * [core] allocate at least 4k buffer for incoming data
  * [core] fix search for header end if split across chunks (fixes #2670)
  * [core] check configparserAlloc() result with force_assert
  * [mod_auth] implement and use safe_memclear, using memset_s or
    explicit_bzero if available (thx loganaden)
  * [core] don't buffer request bodies smaller than 64k on disk
  * add force_assert for many allocations and function results
  * [mod_secdownload] use a hopefully constant time comparison to check
    hash (fixes #2679)
  * [config] check config option scope; warn if server option is given
    in conditional
  * [core] revert increase of temp file size back to 1MB, provide a
    configure option "server.upload-temp-file-size" instead (fixes
    #2680)
  * [core] add '~' to safe characters in
    ENCODING_REL_URI/ENCODING_REL_URI_PART encoding
  * [core] encode path with ENCODING_REL_URI in redirect to directory
    (fixes #2661, thx gstrauss)
  * [mod_secdownload] add required algorithm option; old behaviour
    available as "md5", new options "hmac-sha1" and "hmac-sha256"
  * [mod_fastcgi/mod_scgi] zero sockaddr structs before use (fixes
    #2691, thx Kyle J. McKay)
  * [network] add darwin-sendfile backend (fixes #2687, thx Kyle J. McKay)
  * [core] show correct crypt support result (fixes #2690, thx Kyle J. McKay)


(mef)