Upgrading to Font-Awesome 4.0.3

Reference on Upgrading from 3.2.1
https://github.com/FortAwesome/Font-Awesome/wiki/Upgrading-from-3.2.1-to
-4

Usage:
```
.x-tree-node-collapsed .tree-folder:before {
  @extend %pseudo-font;
  content:$fa-var-folder;
}
```

or:
```
```
.x-tree-node-collapsed .tree-folder:before {
  @include awesome-font; // same as %pseudo-font but usable within
@media
  content:$fa-var-folder;
}
```
```
Updating .tpls to font-awesome 4 markup
Upgrading to Font-Awesome 4.0.3

* origin/pr/11298:
  Updating .tpls to font-awesome 4 markup
  Upgrading to Font-Awesome 4.0.3