[BISERVER-11287] - Settings buttons do not have enough distance.
* Adding a fixed margin of 2 px to pentaho-buttons in this panel.
* Also, marked buttons with "first" and "last" classes, so that, correspondingly, left and right margins are not applied.
Merge pull request #1465 from webdetails/BISERVER-11287

[BISERVER-11287] - Settings buttons do not have enough distance.