Changes in turboEM version 2012.2-1 

   o	first release:  December 2011

   o 	second release: February 2012 
		- allow for parallelization of turboem() using the foreach package
		- added turboSim function to conduct benchmark studies that outputs object of class "turbosim"
		- added option to allow pconstr function to be ignored, even if it is included in turboem() or turboSim() function calls (added use.pconstr as argument to control.method)
		- added check to produce error if "version" of control.method is not specified correctly for decme, pem
		- modified the package vignette to reflect the above changes

Changes in turboEM version 2014.8-1 
	o third release:  August 27, 2014

Changes in turboEM version 2020.1 
   o   	January 2, 2020
	- changed code for detecting "try-error" to conform to the changes in latest R release

Changes in turboEM version 2021.1 
   o   	August 3, 2021
	- added an additional argument to "control" list to allow the algorithm to output a matrix of parameter values at each iteration
