Many small adjustments

- Adjust header width for scrollbar presence
- Added new header assets for grass and dirt
- Adjusted styles for hosted and tracker
- Expand header to implement templating system
- Much more I have forgotten

WebHostLib/static/styles/header/grassHeader.css

@@ -0,0 +1,3 @@
+#base-header{
+    background: url('../../static/backgrounds/header/grass-header.png') repeat-x;
+}