Fix weird tab appearance at certain resolutions

There's 1 physical pixel of error creeping in somewhere which was being
displayed below the selected tab. Workaround it by using a tab texture
which has transparent pixels below the bottom of the select tabs.

src/main/kotlin/net/shadowfacts/cacao/viewcontroller/TabViewController.kt

@@ -7,6 +7,7 @@ import net.shadowfacts.cacao.geometry.Axis
 import net.shadowfacts.cacao.geometry.Point
 import net.shadowfacts.cacao.geometry.Rect
 import net.shadowfacts.cacao.geometry.Size
+import net.shadowfacts.cacao.util.Color
 import net.shadowfacts.cacao.util.MouseButton
 import net.shadowfacts.cacao.util.texture.NinePatchTexture
 import net.shadowfacts.cacao.util.texture.Texture
@@ -239,7 +240,7 @@ class TabViewController<T: TabViewController.Tab>(
 		padding = 2.0
 	) {
 		companion object {
-			val BACKGROUND = Identifier("textures/gui/container/creative_inventory/tabs.png")
+			val BACKGROUND = Identifier("phycon:textures/gui/tabs.png")
 		}
 
 		private var selected = false
@@ -293,7 +294,7 @@ class TabViewController<T: TabViewController.Tab>(
 			val u = when {
 				superview == null -> 0
 				frame.left == 0.0 -> 0
-				frame.right == superview!!.bounds.right -> 140
+				frame.right == superview!!.bounds.right -> 56
 				else -> 28
 			}
 			backgroundView.texture = Texture(BACKGROUND, u, v)