Added third value for inputs.mouse_click_position[] to save where the mousedown happened (1:GUI,2:object,3:tile).
Fixed deselection issue when clicked on object.
Updated todo.
Removed unnecessary selection_clear() on mousedown on a tile.
Corrected cursor_position_in_world[] handling in gfx_render_markers() to calculate the actual coordinates.
Added _2d_equals() helper, player2_build_tower() and call of it in handle_mousedown_tile().
Added ObjectPlayer2Tower2 build and toolbar button for it.