core.Object has __repr__ and not __iter__
core.Object has __repr__ and not __iter__

The __repr__ now returns <CLASS ID 0xMEMORY_LOCATION> so it is clear if
an entity is a string id for a reaction or a reaction itself from the
__repr__. This fixes gh#86

The lack of __iter__ makes it easy to check for lists of core.Object
using duck-typing instead of explicitly using isinstance

jerkos/cobrapy,JuBra/cobrapy,jerkos/cobrapy,JuBra/cobrapy,aebrahim/cobrapy,jeicher/cobrapy,zakandrewking/cobrapy,jeicher/cobrapy,aebrahim/cobrapy,zakandrewking/cobrapy