[Ml-yokadi] Module reorg

[Sébastien Renard]

Hello yokaders !

Yokadi source tree tends to be more and more messy. We have 17 .py files at 
the root. Only tests and update are grouped in folders.

Time to reorganise it isn't it ?

Right now, we keep modules quite small and I like it, but we should create 
package (ie. folder with __init__.py file) to group some modules together.

Here's some propositions : 
- cmd package to group all modules defining do_* commands
- parser package to group YokadiParser and parsingutils
- lib package to group all helpers (tui, colors, dateutils, textrenderer, 
utils). The last one (utils) should be split and reorganise

Executable script (yokadi.py and yokadid.py) should live at root.

I don't know where db.py should go.

If you agree I go on reorg.

a+
-- 
Sébastien