Updated 'HII_ROUND_ERR' to avoid discontinuities of the redshift evolution in power spectra.
Replaced the function 'Mass_limit_bisection' with a simple analytic form, and fixed the interpolation in the high-density region for the SFRD calculation.
Fixed bug when using 'SUBCELL_RSD' without 'USE_TS_IN_21CM' in delta_T.c.