[var] various upgrades to var:

* var is promoted to the main package.
* It is no longer an opt-in thing.
* bug: var (unlike val) is allowed in old-style for loops, but if you multi-init: for (var i = 0, j="Foo";;), you now get an error that you can't do that.
* tests both for the multi-for situation and the new main package variant.

test/transform/resource/after-ecj/VarWarning.java

@@ -0,0 +1,10 @@
+import lombok.var;
+public class VarWarning {
+  public VarWarning() {
+    super();
+  }
+  public void isOkay() {
+    @var java.lang.String x = "Warning";
+    x.toLowerCase();
+  }
+}