Improve a field select design

[rlecellier]

Basicly copy nice stuff from google:

• separator by type : string / list / date
• may be add time
• better labels

[almet]

I love this idea, I would say please, just go ahead !

[sahildua2305]

I'd really like to see different fields like email, numeric etc. This will also serve the purpose of basic user defined validation as mentioned in #177.

[almet]

We just need to take care to how we present these fields to the user: having a lot of different fields seems a good idea at first, but it can clutter the interface :-)

[rlecellier]

We'll to found the place for 3 things do display:

• Widgets: text, textarea, checkbox (+list), radio list, select, etc
• Validators: number, email, etc...
• Shortcuts: "text + email validator", "text + number validator + currency label", etc..

[almet]

I think we are getting too far away with this: the scope of this issue is how to have better labels and design for the field selection. Shortcuts and validators would need to be discussed in a different issue :)