Feature/490 json attributes as object

### Description
The rendering of ContextAttribute for JSON has now two possibilities:
1. As a vector (the old way)
2. As an object, with each attribute as an object inside

(1) is the default rendering method, while the second method is achieved adding the URL parameter

    attributesFormat=object

Fixes issue #490.
Yeah, sorry.
These changes are really really hard to do (many files must be modified) and I'm not going to do it more than once.
Now I have ConnectionInfo in a few more places and adding new stuff (new stuff will be added, don't worry) will be extremely easy. Apart from that, we win in execution time.
Really, ConnectionInfo contains exactly that information that is crucial for the connection and should be visible (on the stack) to all our functions. That is my opinion, at least.

NTC