Set default cache expiry in config

[biskandar-pk]

• Able to cache without any additional querystring cache ( keep it clean )
• Able to force update the cache expiry via querystring ( optional )

[Akeri]

Hi @biskandar-pk, this feature it's very useful, I switched to your branch, thank you.
Hope the maintainer will merge it at some point.
It would also make sense to define a very default cache expiry without need to set it by model.
I see this comment in your code :

var cachExpire = 0; // set default to 5 minutes

but such default it's not working to me.