xspec updates

Bug fixes/updates from Craig. These are all listed on the bugs page.

12.3.1ak	This fixes dummyrsp so it can be applied to any model for a given spectrum, and can now take advantage of XSPEC's recently added multiple sources capability in the same way as the response command. Previously dummyrsp only worked properly for the standard single source cases. This also fixes a Solaris specific bug, which could cause NaN calculation errors when folding a model with a dummy response. Report added on Aug 20, 2007. The fix is to replace headas/Xspec/src/XSModel/Data/ SpectralData.cxx, src/XSModel/Data/Detector/ UserDummyResponse.cxx, src/XSModel/GlobalContainer/ DataContainer.cxx, src/XSUser/Handler/ xsDummyrsp.cxx, xsResponse.cxx, and rebuild xspec.
12.3.1al	Using delcomp to remove a table model component causes a segmentation fault. If editmod is used on a model with a table component, and the component is written with an abbreviated form of "atable", "mtable", etc., editmod erroneously considers it a modified component. Report added on Aug 20, 2007. The fix is to replace headas/Xspec/src/XSModel/Model/ Model.cxx, src/XSModel/Model/Component/ Component.cxx, and rebuild xspec.
12.3.1am	A couple of output formatting improvements: lumin output should be in standard "d.ddde+EE" format and not written as "d.ddd x 10^EE". The margin command output should switch from fixed to scientific format for a wider range of exponent values. Our thanks to Jeremy Sanders for pointing this out. Report added on Aug 20, 2007. The fix is to replace headas/Xspec/src/XSFit/MCMC/ MarginGrid.cxx, src/XSModel/Model/ Model.cxx, and rebuild xspec.