initial adding of big matrix support
1) add big matrix support for bezier coeficient computation.
	bezier.coef.big
	gfit.bezier.big
	bezier.test.big
	gfit.bezier.bchmrk  # compare performace of R matrix and file backed big matrix
2) add resoluation control for gfit.plot
3) replace some headling libray statemenbbt with in-function require statement