refactor list: remove useless variables

Use global size variables instead of specific variables.
feat date picker: add date picker component
chore demo: add date picker link in sidebar
chore demo: moment dependency in installation doc
feat date picker: add label attribute

Add label attribute to specify label on text field.
fix date picker: use moment local locale

Define moment local locale instead of moment global locale.
Merge pull request #61 from lumapps/feat/date-picker

feat date picker: add date picker component
chore changelog: release v0.2.22
feat scrollbar: Create getter & setter to watch scroll percentage

Improve LumX Scrollbar by adding getter and setter on the service. If the id of the scroll element is set, we can $watch the scrollPercent of a specific scrollbar using the getter.
feat scrollbar: Observe id to handle dynamics variables

Before, the id was set in plain text, we can now set a dynamic variable for it.
feat scrollbar: fix jshint error