New directive HttpProtocol which allows to disable HTTP/0.9 support

with min=0.9|1.0 syntax.
    
A tighter restriction off the version in the request line is still
possible with <If "%{SERVER_PROTOCOL_NUM} ..."> .
Submitted by: sf
Backports: r1406719, r1407643, r1425366



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x-merge-http-strict@1767941 13f79535-47bb-0310-9956-ffa450edef68