rewrite soap_device.c

1) separate HTTP handling from SOAP handling
2) remove repeated validity check, each check is performed exactly once
3) fix HTTP status code per UPnP spec, SOAP spec and RFC 2774

Conflicts:
	ChangeLog
	upnp/src/soap/soap_device.c

Signed-off-by: Marcelo Roberto Jimenez <mroberto@users.sourceforge.net>
Fix memory leaks caused by DOMString members.

Signed-off-by: Marcelo Roberto Jimenez <mroberto@users.sourceforge.net>