Gets number of excluded patches from patches_base:
        #patches_base=1.0.0+THIS_NUMBER

def get_n_excluded_patches(self):
        """
        Gets number of excluded patches from patches_base:
        #patches_base=1.0.0+THIS_NUMBER
        """
        base = self.get_patches_base()
        if not base:
            return 0
        p = base.rfind('+')
        if p == -1:
            return 0
        try:
            n = int(base[p+1:])
            return n
        except TypeError:
            return 0