Added syntax definition for Fantom language (#3660)

* Added mgiannini/sublime-factor as a submodule

Provided better color for Fantom
Added license for sublime-fantom
Specified tm_scope for Fantom

* Redirected submodule for Fantom to fork with updated grammar

* Triggering build

* Updating sublime-fantom submodule

* Updated submodule sublime-fantom

* Adding Fantom samples

samples/Fantom/sample2.fan

@@ -0,0 +1,50 @@
+/*
+ * Author: Robert Koeninger
+ * License: WTFPL (http://www.wtfpl.net/)
+ */
+
+mixin Expr
+{
+  abstract Obj? eval()
+}
+
+class Constant : Expr
+{
+  Obj? value
+
+  new make(Obj? value) { this.value = value }
+  override Obj? eval() { value }
+}
+
+enum class Op
+{
+  plus,
+  minus
+}
+
+class Infix : Expr
+{
+  Op op
+  Expr left
+  Expr right
+
+  new make(Op op, Expr left, Expr right)
+  {
+    this.op = op
+    this.left = left
+    this.right = right
+  }
+
+  override Obj? eval()
+  {
+    switch (op)
+    {
+      case Op.plus:
+        return (Int)left.eval() + (Int)right.eval()
+      case Op.minus:
+        return (Int)left.eval() - (Int)right.eval()
+      default:
+        throw Err("undefined Op")
+    }
+  }
+}