XSPEC bug fixes update

Here are the bug fixes from the last month. They can be found in the usual place.

12.5.0w	A new tclout option has been added to make it easier to retrieve the fit parameters' sigma values. The syntax for this option is: tclout sigma [<>:]n where n is the parameter number. If it is not a variable parameter or if the fit was unable to calculate its sigma, a value of -1.0 is returned. Report added on Mar 06, 2009.
12.5.0x	The model.dat entry for the vequil model is missing the parameter for Ar abundance, causing the vequil parameters which follow it to be misinterpreted in the code. (This bug does not affect the equil model.) Report added on Mar 06, 2009.
12.5.0y	The kerrconv convolution model code is still using the xspec11-only LMODDIR environment variable for locating the kerrtable.dat model data file. This should be modified for usage in xspec12, where LMODDIR doesn't exist. Report added on Mar 11, 2009.
12.5.0z	This removes an ambiguous reference build error specific to gcc-4.1.1 on the Solaris-2.9 platform. Our thanks to Dacheng Lin for pointing this out. Report added on Mar 26, 2009.
12.5.0aa	The diskir model goes to infinity when its rirr parameter = 1.0, which is also the default value of rirr's lower limit. Our thanks to Brian Refsdal for pointing this out. Report added on Mar 26, 2009.
12.5.0ab	The nsmax model function is only able to find its auxiliary files when it is run directly from XSPEC's model data directory (heasoft-6.x/spectral/modelData). Our thanks to Stephen Doe for pointing this out. Report added on Mar 31, 2009.
12.5.0ac	Fixes to a couple of obscure cases of gain parameter usage: If a gain parameter belongs to a response temporarily replaced by a dummy response, or a gain parameter is indirectly removed through the data command erasing its associated spectrum and response, the gain shift may still be applied to a response occupying its former spectrum and source number. This patch also improves the show response output. Report added on Apr 06, 2009.
12.5.0ad	The nthcomp model has an uninitialized variable for the case of input energies less than kT_bb/10^4, which may cause a crash to occur. Our thanks to Gulab Dewangan for pointing this out. Report added on Apr 14, 2009.
12.5.0ae	For those linking the models library into their own programs, the swind1 model crashes when outputing a warning message as it indirectly accesses a variable intended for use only in XSPEC. Our thanks to Stephen Doe for pointing this out. Report added on Apr 14, 2009.