Grabs the lines from current figure or figurehandle passed as parameter and passes them into cftool.
Luckily, sequential calls to cftool(xdata,ydata) simply adds that data to cftool gui, so this was easy, but I thought I'd save someone else like me (that didn't want to install EzyFit) the trouble.
The variable name of ydata is set to the 'DisplayName' property of the line because that seems to be the easiest way to set the data set name. Actually changing the display name of the lines in the cftool axis doesn't work because the gui just resets it to the 'ydatavariablename vs xdatavariablename'.
Thanks to those of you that post helpful bits of code. Especially the person I stole the method to access the cftool axes from (cited in script).