Remove the claimed sector borders and add stone terrain

[CHARLI]

I think will be better if the ugly (blue/red) borders are removed after conquering a new sector on the home island.
Similar idea can be if the borders are removed once after the conquering the whole island...
... or make it as player option.. but that's much more complicated.
Also I would like if we can build a stone terrain. The roads are looking great... but this can be added as option to make places of our islands looking better.

[peck_ed]

Don't forget that you still need a storehouse in each sector though! Unless you would suggest this is also removed

[Dragavon]

I would really like to get rid of the border markers too.

storehouses dont have anything t do with that.....