Incubated modules for Phobos

[Piotr Szturmaj]

Hi all,

Normal Phobos submission procedure is usually like that:

1. write entire module from scratch by oneself
2. submit for voting
3. rewrite wrong parts, if there are none then add it to Phobos
4. otherwise goto 2

It is hard for one person to write entire module in such way it 
satisfies everyone, especially for very new or complex additions, such 
as database handling or cryptography.

Here, I propose that we add experimental "exp" hierarchy to Phobos for 
such projects. I know etc hierarchy may me used for that but IMHO 
separate "exp" would be more appropriate. In this namespace "beta" 
modules will slowly evolve into official std modules.

Some (obvious) advantages are:

* developers may receive feedback very early in the process, saving them 
from mass rewrites when in the opinion of community they made some wrong 
coding decission.
* developers may receive coding help, i.e. many of them may collaborate 
on one big module.
* users may test experimental modules early. This is important, because 
usability issues may be catched earlier, not after submission when API 
usually becomes frozen and it is too late.

"Exp" code may be shipped with each release just like "etc" code. Users 
using experimental code should be aware of breaking changes that may be 
introduced with each release or even with each commit.

Thoughts?