*Title: Display information for datatypes

*Incentive:
Make it possible for templates to find information to the
display of a datatype in a specific viewmode.
E.g to group multiple input elements in a fieldset tag.

*Documentation:
Two new attributes are available on an object attribute:
- display_info - Returns info for the object
- class_display_info - Returns info for the class (same as display_info on class)

One new attribute is available on a class attribute:
- display_info - Returns info for the class

Object display info structure:
- edit - Settings related to content edit mode
  - grouped_input - Whether to group all input fields when displaying them
- view - Settings related to content view mode
- collection - Settings related to information collection mode
  - grouped_input - Whether to group all input fields when displaying them
- result - Settings related to information result mode

Class display info structure:
- edit - Settings related to content edit mode
  - grouped_input - Whether to group all input fields when displaying them
- view - Settings related to content view mode

Example template usage:
{section show=$attribute.display_info.edit.grouped_input}
<fieldset>
{section-else}
<label>Name</label>
{/section}

INI settings:
datatype.ini controls the default behaviour of the returned information.
EditSettings:
- GroupedInput - Contains a list of datatypes that will have its input grouped
CollectionSettings:
- GroupedInput - Contains a list of datatypes that will have its input grouped
ClassEditSettings:
- GroupedInput - Contains a list of datatypes that will have its input grouped