Integration of astropy.units in sunpy codebase

Attempt to integrate the astropy.units into sunpy. Every function that were taking or giving a quantity now must have astropy quantity associated with them. Please tell me if I have made mistakes anywhere, or if it could be done in better way, I will make changes! 
Thank you!   
@dpshelio This returns an empty list. I am guessing something something in `vso.VSOClient().query()` has to be changed. I am not sure what though.