Fix a big memory leak bug related to arbitrarily large header lines.

The core input filter would happily consume all the data you gave it
in a header line, looking for that one LF. This patch limits that
"getline" functionality to HUGE_STRING_LEN (8192 bytes).


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@91711 13f79535-47bb-0310-9956-ffa450edef68