Feature/break actions

[BeritJanssen]

Close #251 . Close #599 . Instead of introducing a new Sequential action, or adding information to the next_round array, I found a much less invasive way of accomplishing views with some either/or logic, such as Plink or SongSync: in the config of a Trial, pass along conditions under which the current next_round array is not handled to the end, but new round data requested from the server instead.

To do:

• check scoring is correct
• check that styles are correct
• correct round numbering

[Evert-R]

SongSync with external files isn't working. In the SongSync wrapper the play_method isn't set, so it defaults to buffer. This was previously set in the config of SongSync, because playAudio was called from there.
In hooked.py this is set as a constant at the top of the file, so maybe we can add this as an argument for song_sync from there, so it can be set from the rules file.

[BeritJanssen]

Ah, good catch! In the meantime, I've started working on #561 - in there, I introduce logic that sets the play method based on the path / duration of the file, so hopefully these kind of oversights can be also prevented in the future.

[Evert-R]

Styling bug:
In categorization the playbutton moves down everytime you push a button, except when a feedback smiley is presented.

[BeritJanssen]

Can you share a screen capture of this problem? I think this only occurs after passing the training phase, right?

[BeritJanssen]

I fixed the spacing of the buttons (the main difference with the current develop branch). Will make a separate issue of the jumping buttons - this is unrelated. It already happens in the current develop branch.