How do I only allow collisions between the player and NPC's?

How do I make it so the player can't pass through NPC's, but NPC's can pass through each other?

Like in this example, the NPC's can pass through each other but the player can't pass through NPC's.

http://i.imgur.com/Av28Qt5.gifv

I did this in construct 1, but how do I do it in construct 2?

Here is the construct 1 cap: https://www.mediafire.com/?zas29rxm205u8o7

Don't you have a construct 2 file for this?

No because I couldn't figure out how to do this in construct 2, but eventually I found some solutions to this issue and I listed them here: