[FEATURE] Add date range and interval ViewHelpers
[TASK] Fix unused/misspelled variables
[TASK] Fix typo
[TASK] Remove obsolete files
[TASK] Refactor viewhelper

These changes should reflect the discussion in #154
Merge pull request #155 from bjo3rnf/cleaner

[TASK] General code cleaning
[TASK] Rename attribute "dateFormat" to "format" on Format / DateRange ViewHelper

In addition, expand a chained variable assignment for better clarity.
[DOC] Add doc block for Format / DateRange ViewHelper
Merge pull request #4 from NamelessCoder/spaceglue

[TASK] Rename attribute "dateFormat" to "format" on Format / DateRange ViewHelper
[TASK] Correct package namespace
[TASK] Remove superfluous properties
Merge pull request #154 from bjo3rnf/spaceglue

[FEATURE] Add date range and interval ViewHelpers