2011-05-25  Youyi Fong  <yfong@fhcrc.org>

    * added enhanced.ipw.coxph

2013-08-28  Youyi Fong  <yfong@fhcrc.org>

    * incorporate most common functions from surrograte_0

2014-10-08  Youyi Fong
	* change name from stm to sptm, because stm has been taken
	* phase2.p in sim.fong changes, and unit testing code has to change
	too

