more consistent formspec size decision

init.lua

@@ -49,6 +49,8 @@ local ui = unified_inventory
 ui.style_full = {
 	formspec_x = 1,
 	formspec_y = 1,
+	formw = 17.75,
+	formh = 12.25,
 	pagecols = 8,
 	pagerows = 10,
 	page_x = 10.75,
@@ -80,6 +82,8 @@ ui.style_full = {
 ui.style_lite = {
 	formspec_x =  0.6,
 	formspec_y =  0.6,
+	formw = 14,
+	formh = 9.75,
 	pagecols = 4,
 	pagerows = 6,
 	page_x = 10.5,