v.7

- Fixed bugs:

    - Now you can't move objects after you have pressed Play/Step buttons;
    - Fixed a plenty of bugs in editor;

- Added levels 4-1 - 4-10;

- Edited comments so things get clearer;

- New objects:

    - Lily: Can be placed on water. Bugs can walk on lilies. Lilies drown after something walks on it;
    - Deep water: works as the grass but only for lilies.