pyIRSF-2.2.1 released

• the extended image of counting the number of combined frames had -32 bit. it was changed to 16 bit.
• There was a minor bug in the final file cleaning process. Not found error occured in some cases. It was fixed.
• A parameter 'isigma' was added to recom.param, which is lsigma and hsigma in IRAF's imcombine and affetcs the final combining process of registered images.