Okay, so at the end of the film. Batman is on the mountain facing a city being rebuilt. Superman joins him, "look at it, it's beautiful, what do you see?"

"Promise, hope. I was wrong, about everything. I just wanted to say sorry..... I still won the fight though." - Batman says

"Oh no you didn't I let you win!" They handshake...

Wonder Woman shows up, "what's going on here"

"Just mending fences" Bruce says, are they coming?

The rest of the league shows up...

They are in the sun....

They are smiling

"You will give the people of earth an ideal to strive towards, they will rest behind you, they will fall, but in time they will join in the sun Kal...."

Fade to black

In time, you will help them accompish wonders

Black...

As for Clark, they didn't really explain that, because it would have killed the flow. The ending was long and they had to tie up loose ends so they didn't have time. They did however address him seeing Lois (they get married and the league shows up, not in costume).

After the big battle, DINNER at Martha's house in Costume! Very emotional moment between Martha and Clark!