- Corrected and cleaned up rotation calculation
- Fixed button position/size issues (clickable area didn't correspond to the button image)
- Fixed tool flashing during resizing
- (new feature) Buttons now scale proportionally to the protractor when it is resized
- Everything is now drawn by default at a scale of 1 instead of 1.5
- Pen width set to 0 (i.e always 1 pixel thick regardless of zoom), to keep the old look & feel
- Scaled the marker tool image (.svg) to look like it did before without scaling it in code
- Removed debug messages

Tested on OS X, works fine.

TODO:
 * nice icon
 * nice brush
 * fix draw with marker

Fixed a bug - grouped items cannot be dragged by itself now.

It's icon is temporary.

Behavior implemented:
1. Can interact with all items without showing items frames (but ToolBar shows).
2. Cannot move items, but can drag images.
3. Selected items appears deselected when Play tool chosen.
4. Play tool don't requires selecting of item before interacts.
5. Cursor looks like tool icon in text and image widgets (should be the same in any others widgets, but now in w3c is not).