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/theme.txt

@@ -0,0 +1,22 @@
+title-text: ""
+desktop-image: "/splash.png"
+terminal-width: "800"
+terminal-height: "600"
++ boot_menu {
+		top = 40%
+        left = 24%
+        width = 60%
+		height = 20%
+		item_color = "#AAAAAA"
+		selected_item_color = "#FFFFFF"
+        item_spacing = 1
+}
++ progress_bar {
+        id = "__timeout__"
+        top = 90%
+        left = 30%
+        width = 40%
+        height = 1
+        bg_color = "#000000"
+        fg_color = "#4444DD"
+}