Make responsive the toolbar in Physics activity

[llaske]

In Sugarizer it's important that whatever could be the screen size the Stop button is always visible to be sure the user will be able to quit the activity. So responsive activities use media queries in CSS file to hide other toolbar buttons depending of the window size. See for example Paint activity behavior:

The Physics activity toolbar is not fully responsive as you could see below:

[deadnamedimmer]

Working on it!

[llaske]

Fixed in #529

[Swayamsvk]

Is this issue open?

[llaske]

Issues are open until integrated in a release but as mentioned above by the "Fixed in #XXX" and the tag "to be release", no action is need on this issue.