proof of concept of merging lookups to customization points for model

[burlog]

Hi, before merging this please comment on the list.

[mjcaisse]

Hi Michal, I'm catching up from last week and want to respond to your ML posts. Thanks for the PR. I'll take a look at this too and then start a discussion about the approaches.

[rmpowell77]

Lots of whitespace changes...

One concern, I think I have to do specialization like this:

namespace boost { namespace boostache { namespace model { namespace customization {

template <>
void render<std::ostream, MyObject>(std::ostream & stream, MyObject const & v)
...
}}}}

Don't have my compiler ready, but I don't think you can do partial specialization of functions, so it's a little obtuse

Also, is it usual for specializations to have to occur in such a deep namespace? (not familiar with other approaches...)

[burlog]

Sorry for whitespaces, it's partly due to editor and bad habbit :(. I had to split to more commits.
But we should choose count of indetation spaces (we have 2 3 4 in code... )

Yes you can't do partial specialization of functions....

We can choose other namespace, I used it because it was here yet...