exit_*_mode should return to the previous mode

[eugenesvk]

I've mapped a few commands in insert mode to use the select mode for quick selection without mode switch
Currently I have to add insert_mode at the end of every command, but originally I expected he exit_select_mode to return to the previous mode instead of returning to the normal mode, so I think exit should behave the other way around - if you need to get back, you use exit, if you need to get to normal mode, you use normal_mode