Add a delete button in the new idea input field of Labyrinth activity

[llaske]

The new idea input field into the Labyrinth activity miss a delete button to delete the whole content of the field. So, it's difficult to completely remove the content, specifically on tablets.

The idea is to add a delete button into the input field: the same button that the one in the Search activity in Sugarizer home view.
Styles to do that are described in the sample here: http://sugarlabs.github.io/sugar-web-samples/iconinputtext.html

Source code for the Labyrinth activity is available here: https://github.com/llaske/sugarizer/tree/dev/activities/LabyrinthJS.activity

[lohani2280]

@llaske I would like to work on this issue.

[llaske]

Sure. Feel free to work on it.

[llaske]

Fixed in #267. To be release.

[llaske]

Closed in dd3c58d