[Functional] Becke-Roussel not having an closed-form expression

[DyeKuu]

This will affect the following functionals:

gga_x_fd_lb94          # Becke-Roussel not having an closed-form expression
gga_x_fd_revlb94       # Becke-Roussel not having an closed-form expression
gga_x_gg99             # Becke-Roussel not having an closed-form expression
gga_x_kgg99            # Becke-Roussel not having an closed-form expression
hyb_gga_xc_case21      # Becke-Roussel not having an closed-form expression
hyb_mgga_xc_b94_hyb    # Becke-Roussel not having an closed-form expression
hyb_mgga_xc_br3p86     # Becke-Roussel not having an closed-form expression
mgga_c_b94             # Becke-Roussel not having an closed-form expression
mgga_x_b00             # Becke-Roussel not having an closed-form expression
mgga_x_bj06            # Becke-Roussel not having an closed-form expression
mgga_x_br89            # Becke-Roussel not having an closed-form expression
mgga_x_br89_1          # Becke-Roussel not having an closed-form expression
mgga_x_mbr             # Becke-Roussel not having an closed-form expression
mgga_x_mbrxc_bg        # Becke-Roussel not having an closed-form expression
mgga_x_mbrxh_bg        # Becke-Roussel not having an closed-form expression
mgga_x_mggac           # Becke-Roussel not having an closed-form expression
mgga_x_rpp09           # Becke-Roussel not having an closed-form expression
mgga_x_tb09            # Becke-Roussel not having an closed-form expression

In libxc, the calculation is done using Brent's method.