feat search-filter: create search filter component

http://www.google.com/design/spec/components/text-fields.html#text-field
s-search-filter
chore demo: add search filter example
chore demo: fix css search filters toolbar
chore demo: fix space in demo html file
feat search-filter: ergonomic improvements

On a search filter opened by default, when a click is outside the
search filter, it closes the search input. But if the user clicks ont
the icon label, it no longer closes the search filter.
feat search-filter: better click handlers

The click handlers were created with the component creation. Thus, the click "outside"
the element was detected event though the search field was not active.
This commit create the click handlers when the search field is opening, and delete them
when the search field is closing. It fix the memory leaks and optimizes performances.
Merge pull request #7 from lumapps/feat/search-filter

feat search filter: add search filter components