Refactor JForStatement construct.

The third part of a JForStatement can only be a list of expressions.
This patch changes its representation from a List<JExpressionStatement>
to a JExpression (which in some cases will be a JMultiExpression).

Some later passes, such as CompoundAssignmentNormalizer are simplified
as a result (in a following patch).

Change-Id: Ice90e323698ef5ec24ff744df04ee0c182d0e7e9
Enable Super Dev Mode for samples that use Ant

Also enables Super Dev Mode by default in Ant
projects created using webAppCreator.

Change-Id: Ia515696a420adbead2d9776330d430b4ab428c04
Merge remote-tracking branch 'upstream/master'