[mod_accesslog] fix log buffer <-> log file mapping

git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@2886 152afb58-edef-0310-8abb-c4023f1b3aa9
[ssl] Fix $HTTP["scheme"] conditional, could be "http" for ssl connections if the ssl $SERVER["socket"] conditional was nested (fixes #2501)

con->conf.is_ssl got removed and replaced by:
 * con->conf.ssl_enabled for the config var "ssl.engine" - it is only
   used to determine which server-sockets should use ssl. (usually not
   needed as it is mandatory and enough to set ssl.pemfile anyway)
 * con->srv_socket->is_ssl to detect the actual ssl status of the
   bound socket, which is the same as the ssl status of the connection
 * con->uri.scheme for the actual $HTTP["scheme"] value, also used for
   the CGI "HTTPS=ON" variable. This defaults to "https" if the
   connection uses ssl, but can be changed for example by mod_extforward
   if X-Forwarded-Proto: is set to either "http" or "https" (other values
   are ignored right now)

Also removed the broken srv_socket->is_proxy_ssl as it was a connection
value in a server_socket struct...

git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@2887 152afb58-edef-0310-8abb-c4023f1b3aa9
[autoconf] pkg-config: search for lua5.1 and lua-5.1 before lua

git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@2888 152afb58-edef-0310-8abb-c4023f1b3aa9