fix a small SNR inaccuracy: the background was being calculated based on the mouse click position or the previous star position; it should be based on the aperture around the current peak pixel
fix a small SNR inaccuracy: the background was being calculated based on the mouse click position or the previous star position; it should be based on the aperture around the current peak pixel

simonct/phd2,simonct/phd2,EverettQuebral/phd2,EverettQuebral/phd2,OpenPHDGuiding/phd2,olegkutkov/phd2guiding_crao,OpenPHDGuiding/phd2,simonct/phd2,EverettQuebral/phd2,OpenPHDGuiding/phd2,olegkutkov/phd2guiding_crao,hholi/phd2,simonct/phd2,olegkutkov/phd2guiding_crao,hholi/phd2,hholi/phd2,simonct/phd2,OpenPHDGuiding/phd2,EverettQuebral/phd2,hholi/phd2,simonct/phd2,EverettQuebral/phd2,olegkutkov/phd2guiding_crao,hholi/phd2,olegkutkov/phd2guiding_crao,OpenPHDGuiding/phd2,hholi/phd2,EverettQuebral/phd2,olegkutkov/phd2guiding_crao,OpenPHDGuiding/phd2