Change blc_command_add removing the need of const in the callback. WARNING This affects all the function using it

Try to quit normally (blc_status=BLC_QUIT) while receiving SIGTREM the first time, the second time, use exit()

Try to quit normally (blc_status=BLC_QUIT) while receiving SIGTREM the first time, the second time, use exit()

Add 'blc_command_forward_blc_channels' to make blc_command_loop automatically forward blc_channels without interpreting it