Show Animated GIF and Video MP4 commands to aid debugging

[1fifoto]

Add message for each image capture to understand when image capture takes place and when Animated GIF and Video MP4 creation takes place. To clearly show users what is taking place display the actual commands issued for Animated GIF and Video MP4 creation. This is in preparation to debugging the "TODO These may not get called after the end of the capture_image process..."

Adding

Capture picture: 0
Capture picture: 1
Capture picture: 2
Capture picture: 3
Capture picture: 4
Capture picture: 5
Capture picture: 6
Capture picture: 7
Capture picture: 8
Capture picture: 9

For example, change from

Creating animated gif.
Creating video.

to

Creating animated gif: convert -delay 10 -loop 0 /home/pi/Desktop/pi-timelapse/series-2018-12-20_18-43-32/image*.jpg /home/pi/Desktop/pi-timelapse/series-2018-12-20_18-43-32-timelapse.gif
Creating video: avconv -framerate 20 -i /home/pi/Desktop/pi-timelapse/series-2018-12-20_18-43-32/image%05d.jpg -vf format=yuv420p /home/pi/Desktop/pi-timelapse/series-2018-12-20_18-43-32/timelapse.mp4