Use Segoe UI for Latin characters before falling back to YaHei (#3616)

* Use Segoe UI for Latin characters before falling back to YaHei

This fixes issues with character rendering on hidpi displays and other
aliasing/hinting issues, as Segoe UI has been painstakingly hinted by
typographers for Microsoft while YaHei has not. See #3237 for more
details.

Closes #3237

* Include transformed LESS -> CSS in commit

public/less/_base.less

@@ -1,7 +1,7 @@
 @footer-margin: 40px;
 
 body {
-    font-family: "Lato", "Microsoft YaHei", Arial, Helvetica, sans-serif !important;
+    font-family: "Lato", "Segoe UI", "Microsoft YaHei", Arial, Helvetica, sans-serif !important;
     background-color: #fff;
     overflow-y: scroll;
     -webkit-font-smoothing: antialiased;