Manual improvement

Hello all,

I'm currently working on Czech translation of the manual and
I came
across a thing, which can be written in a better-explain
way.

It is just a tiny bit in Zend_Json-Objects.xml on line 29

instead of:
// Decode objects as objects

can be:
// Decode JSON objects as PHP objects


I know, it is not so important, but why not make the manual
even better 


Regards


Martin.