[Minor update] Added advanced slope, camera rotating, photography mode, etc.

Hi there, I brought the update summary of these days: [h3]New content[/h3] [list] [*] New building: Advanced Slope by unlocking the research Expressway. [*] New feature: Photography mode. you can enter photo-mode by clicking the button in right up of the screen. It will hide the interface and most HUDs. [*] New camera rotating operation: right-click and drag to adjust the viewing angle, home or double-click the middle button to restore the default. [/list] [h3]Remove content[/h3] [list] [*] Removed event: Rogue Robots. [/list] [h3]Improvement[/h3] [list] [*] Improve frame rate: Reduce some related performance consumption when there are a lot of materials on the terrain or a lot of blueprints to be built. [*] The grid height of the surface is now also displayed in the area view. [*] When sorting money in the population interface, the money of androids is defaulted to 0 [*] Research interface operation improvement, use the scroll wheel to scroll left and right, and only zoom when holding down ctrl. [*] Fix the problem that materials on the terrain are sometimes not counted. [/list] Wish you have fun~