IterationTag support

Classes Modified

TagBeginGenerator

• The return value of doStartTag() is now checked against EVAL_BODY_BUFFERED instead of EVAL_BODY_TAG. EVAL_BODY_TAG is deprecated, and both have the same integer value so we only check against EVAL_BODY_BUFFERED.

TagEndGenerator

• doAfterBody() is now called if tag is an instance of IteratorTag (instead of if it is an instance of BodyTag)
• The return value of doAfterBody() is now checked against EVAL_BODY_AGAIN instead of EVAL_BODY_TAG. EVAL_BODY_TAG is deprecated, and both have the same integer value so we only check against EVAL_BODY_AGAIN.