[build] Rename gPXE to iPXE

Access to the gpxe.org and etherboot.org domains and associated
resources has been revoked by the registrant of the domain.  Work
around this problem by renaming project from gPXE to iPXE, and
updating URLs to match.

Also update README, LOG and COPYRIGHTS to remove obsolete information.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/core/init.c

@@ -18,8 +18,8 @@
 
 FILE_LICENCE ( GPL2_OR_LATER );
 
-#include <gpxe/device.h>
-#include <gpxe/init.h>
+#include <ipxe/device.h>
+#include <ipxe/init.h>
 
 /** @file
  *
@@ -31,7 +31,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 static int started = 0;
 
 /**
- * Initialise gPXE
+ * Initialise iPXE
  *
  * This function performs the one-time-only and irreversible
  * initialisation steps, such as initialising the heap.  It must be
@@ -49,7 +49,7 @@ void initialise ( void ) {
 }
 
 /**
- * Start up gPXE
+ * Start up iPXE
  *
  * This function performs the repeatable initialisation steps, such as
  * probing devices.  You may call startup() and shutdown() multiple
@@ -71,11 +71,11 @@ void startup ( void ) {
 }
 
 /**
- * Shut down gPXE
+ * Shut down iPXE
  *
  * @v flags		Shutdown behaviour flags
  *
- * This function reverses the actions of startup(), and leaves gPXE in
+ * This function reverses the actions of startup(), and leaves iPXE in
  * a state ready to be removed from memory.  You may call startup()
  * again after calling shutdown().
  *