Move to template format instead of cat-EOF

Simplifies the scripts and adds the ability to easily and cleanly change
the contents of these files without dealing with escape characters, etc.

templates/grub.cfg

@@ -0,0 +1,34 @@
+set theme=($root)/boot/grub/theme.txt
+set gfxmode=800x600
+set gfxpayload=keep
+insmod efi_gop
+insmod efi_uga
+insmod video_bochs
+insmod video_cirrus
+insmod gfxterm
+insmod png
+terminal_output gfxterm
+background_image /splash.png
+
+insmod play
+play 960 440 1 0 4 440 1
+if [ ${iso_path} ] ; then
+  set loopback="findiso=${iso_path}"
+fi
+
+set timeout=10
+menuentry "PVC Live Installer" {
+  echo -en "\n\n\n\n\n\n\n\n\n\n\n\t\t\tBooting PVC live installer..."
+  linux  /live/vmlinuz boot=live components splash quiet "${loopback}"
+  initrd /live/initrd.img
+}
+menuentry "Traditional Debian Installer (graphical)" {
+  echo -en "\n\n\n\n\n\n\n\n\n\n\n\t\t\tBooting Debian installer (graphical)..."
+  linux  /d-i/gtk/vmlinuz append video=vesa:ywrap,mtrr vga=788 "${loopback}"
+  initrd /d-i/gtk/initrd.gz
+}
+menuentry "Traditional Debian Installer (console)" {
+  echo -en "\n\n\n\n\n\n\n\n\n\n\n\t\t\tBooting Debian installer (console)..."
+  linux  /d-i/vmlinuz  "${loopback}"
+  initrd /d-i/initrd.gz
+}