Improve record/play features

[guillefix]

Short term

• Add history-like list to recording
• Make sure it works with undo/redo

Mid term

• Make it possible to give titles and descriptions to certain steps, which are then displayed when playing back

Long term

• Add milestone steps to recording and export recording to an HTML presentation which uses a library like impress.js
• Make the presentation editable in a web interface like strut.io to add other things

[guillefix]

I'm going to add the recorded steps as part of the history and make it appear in the history list with a red highlighting.

[guillefix]

Update manipulations in "play next" function