[grub] update embedded GRUB to 2.06

* Also enable NTFS and ext# as GRUB2 compatible file systems.

res/appstore/Package.appxmanifest

@@ -11,7 +11,7 @@
   <Identity
     Name="19453.net.Rufus"
     Publisher="CN=7AC86D13-3E5A-491A-ADD5-80095C212740"
-    Version="3.15.1803.0" />
+    Version="3.15.1804.0" />
 
   <Properties>
     <DisplayName>Rufus</DisplayName>

res/grub2/grub2_version.h

@@ -2,4 +2,4 @@
  * This file contains the version string of the GRUB 2.x binary embedded in Rufus.
  * Should be the same as GRUB's PACKAGE_VERSION in config.h.
  */
-#define GRUB2_PACKAGE_VERSION "2.04"
+#define GRUB2_PACKAGE_VERSION "2.06"

res/grub2/readme.txt

@@ -1,17 +1,14 @@
 This directory contains the Grub 2.0 boot records that are used by Rufus
 
 * boot.img and core.img were created from:
-    https://ftp.gnu.org/gnu/grub/grub-2.04.tar.xz
-  with the following 3 extra patches applied:
-  - https://lists.gnu.org/archive/html/grub-devel/2020-07/msg00016.html
-  - https://lists.gnu.org/archive/html/grub-devel/2020-07/msg00017.html
-  - https://lists.gnu.org/archive/html/grub-devel/2021-03/msg00012.html
-  on a Debian 10.x x64 system using the commands:
+    https://ftp.gnu.org/gnu/grub/grub-2.06.tar.xz
+  on a Debian 10.9 x64 system using the commands:
     ./autogen.sh
+    # --enable-boot-time for Manjaro Linux
     ./configure --disable-nls --enable-boot-time
-    make -j6
+    make -j4
     cd grub-core
-    ../grub-mkimage -v -O i386-pc -d. -p\(hd0,msdos1\)/boot/grub biosdisk part_msdos fat ntfs exfat -o core.img
+    ../grub-mkimage -v -O i386-pc -d. -p\(hd0,msdos1\)/boot/grub biosdisk fat exfat ext2 ntfs ntfscomp part_msdos -o core.img
 
 * boot.img has been modified to nop the jump @ 0x66 as per grub2's setup.c comments:
   /* If DEST_DRIVE is a hard disk, enable the workaround, which is