Update to iPXE version to 1.21.1

- Build additional artifacts - ISO, UEFI, etc.
- Set default timeout on shell to fallthrough on failures
- Add ping command (enabling patch renamed to be more generic)
- Update build container to Debian 11
- Add VERSION file

Change-Id: I9476c1d6446f6943dcd084384ba2ae3d96f71128
diff --git a/patches/features.patch b/patches/features.patch
new file mode 100644
index 0000000..62702f9
--- /dev/null
+++ b/patches/features.patch
@@ -0,0 +1,22 @@
+diff --git a/src/config/general.h b/src/config/general.h
+index 0c99bcbb..04ced76c 100644
+--- a/src/config/general.h
++++ b/src/config/general.h
+@@ -54,7 +54,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+ #define	DOWNLOAD_PROTO_TFTP	/* Trivial File Transfer Protocol */
+ #define	DOWNLOAD_PROTO_HTTP	/* Hypertext Transfer Protocol */
+-#undef	DOWNLOAD_PROTO_HTTPS	/* Secure Hypertext Transfer Protocol */
++#define	DOWNLOAD_PROTO_HTTPS	/* Secure Hypertext Transfer Protocol */
+ #undef	DOWNLOAD_PROTO_FTP	/* File Transfer Protocol */
+ #undef	DOWNLOAD_PROTO_SLAM	/* Scalable Local Area Multicast */
+ #undef	DOWNLOAD_PROTO_NFS	/* Network File System Protocol */
+@@ -148,7 +148,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+ //#define PCI_CMD		/* PCI commands */
+ //#define PARAM_CMD		/* Form parameter commands */
+ //#define NEIGHBOUR_CMD		/* Neighbour management commands */
+-//#define PING_CMD		/* Ping command */
++#define PING_CMD		/* Ping command */
+ //#define CONSOLE_CMD		/* Console command */
+ //#define IPSTAT_CMD		/* IP statistics commands */
+ //#define PROFSTAT_CMD		/* Profiling commands */