Update translations
Update changelog with a missing change.
Update version
Added tag v2.2.1 for changeset ca04199a41a4
Add new breakpoint icons because the old ones had poor resolution
Rename 'control.png' icon to 'arrow-continue.png'
Debug toolbar: Change continue and stop icons

- The continue icon was exactly the same as a play one and that was confusing
people coming from Matlab.
- The idea of the stop icon is getting closer to the model of 'recording' icons
generally used for play/stop actions (Matlab also follows this pattern).
Run toolbar: Add a new set of icons for it

- The old icons were criticized as being too skeuomorphic
Run toolbar: Adjust the size of all its icons to make them look better
Debug toolbar: Add a new icon for the debug action
Debug toolbar: Make continue icon a bit bigger
Main toolbar: Change the icons for maximize and unmaximize plugins

- The maximize icon is nowadays used to represent "go to full screen" so it was
necessary to change it.
Main toolbar: Change fullscreen icons according to up to date conventions
Main toolbar: Modify maximize and unmaximize icons a little bit to better match the fullscreen ones
Run toolbar: Change run icon because it didn't scale well on the Run menu
Debug toolbar: Change debug icon aspect ratio to make it render better
Breakpoints: Adjust size of breakpoint icon

- It was 16px and it's now 15px because it appeared too big next to the text.
Debug Toolbar: Improve tooltips of several buttons to make their actions easier to understand
Breakpoints: Reduce their icon sizes even more because they were still too big
Breakpoints: Add a bigger version of their icons and put it on the Run menu

- This is necessary because the small version was seen pixelated on the menu.