deconstruct_and_eval2 simplified and excluded "indicator" class from evaluation. Following now works (was issue with "Close" eval):

Close <- indicator( Close, input=OHLCV)
SMA <- indicator( SMA(Close, nsma), input=OHLCV)
introduced sfl - strategery formula language, for complete delayed evaluation. reorganizes indicator and rule classes. eliminates signal class (almost duplicit to indicator class)
resolves #13