Implement Images for helpers

[GSoster]

Helpers should be represented in a graphic way.
The default file extension should be .png but it is necessary to think about animated images (.gif) too.

[GSoster]

Part of this was already made on commit 7e7bb51
The current graphic representation implemented is: graphics folder/ helperName + extension.
In the way it is implemented right now it is possible to have only one extension to all helpers/cursors.

graphicRepresentation: __custom_settings.helpers_graphics_folder + name + __custom_settings.helpers_graphics_extension

it still necessary to add gif support.