xspec patches 12.7.0l-o

12.7.0l	A crash can occur when trying to plot data while using a dummy response with no channel array. Our thanks to Randall Smith for pointing this out. Report added on Oct 05, 2011.
12.7.0m	An enhancement for PyXspec. This adds the new function AllModels.simpars(), which provides the same functionality as standard XSPEC's tclout simpars command. The simulated parameter values are returned as a tuple of floats. Our thanks to Martin Sparre for this suggestion. Report added on Oct 05, 2011.
12.7.0n	A fix for PyXspec. When a Parameter object's frozen attribute is toggled (to either freeze or thaw the parameter), the fit statistic's degrees-of-freedom doesn't get updated until a new fit is performed. It ought to be updated immediately. Our thanks to Sebastien Guillot for pointing this out. Report added on Oct 05, 2011.
12.7.0o	An enhancement for PyXspec. This adds the new attribute Fit.covariance, which holds (in a tuple) the covariance matrix values from the most recent fit. Our thanks to Sebastien Guillot for this suggestion. Report added on Oct 11, 2011.