search for: pxenv_restart_http

Now that pxechain.com can work (with my patch to core/pxelinux.asm), a PXE Chainload COM32 is not as big of a deal but I agree with HPA that it would be a good idea, especially considering the possible flexibility that this may allow. For the moment, I've named the chain module pxechn.c32 in order to not collide with the name pxechain.com when not specifying the .com/.c32 extension.