[core] chunkqueue_get_append_newtempfile()
[core] chunkqueue_get_append_newtempfile()

rename chunkqueue_get_append_tempfile()
    -> chunkqueue_get_append_newtempfile()

pull some code from chunkqueue_append_mem_to_tempfile()
  into smaller func for (new func) chunkqueue_get_append_tempfile(),
  which might call into chunkqueue_get_append_newtempfile()

pull some code from chunkqueue_append_mem_to_tempfile()
  into smaller func chunkqueue_append_tempfile_err()
  to handle write errors with respect to removing empty chunk
  and stepping to next configured tempdir

lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4