Trapping a crash when plotting and a new tclout option

12.7.0t	Fix for a crash which may occur when attempting to plot data for a spectrum which contains no noticed channels. Our thanks to Eduardo Ojero Pascual for pointing this out. Report added on Jan 03, 2012.
12.7.0u	This adds a new tclout option, tclout rerror, which is necessary for retrieving the results of an rerror command run on gain parameters. The syntax for this is: tclout rerror [< source number>:]< gain par number> Our thanks to Matteo Guainazzi for bringing this to our attention. Report added on Jan 18, 2012.