Load images when they are needed

[humitos]

Typing Turtle is loading all the SVG images (62 images) at startup. This makes the activity to spend some time at the beggining and to consume to much memory.

I think it should load the SVG images at the moment they are needed by the activity.

This is the chunk of code (keyboard.py L#138) that is doing this work:

for filename in glob.iglob('images/OLPC*.svg'):
    image = GdkPixbuf.Pixbuf.new_from_file_at_scale(
        filename, scale_width, self.height, False)
    name = os.path.basename(filename)
    self.images[name] = image

[godiard]

FIxed on ​https://github.com/godiard/typing-turtle-activity/commit/356b9b8f1771c4d23c5f14d595d7bd60228a8810