Panoramic cameras, spawnpoints and environment

Addition of multiple cameras on the map: taking panoramic photos is now
much easier. Remove all dense rainforest ground branches: the visual
effect is different with the distance and it looks pretty bad. Main
layer cleaned: last object moved to the "Environment" layer. Fuel island
cleaned to prepare the construction: some rocks removed, all layer
painting cleaned. Some unused spawnpoints are removed. All spawnpoints
are renamed with an individual name and the layer's name is changed from
"SpawnPoint" to "Spawnpoint". Addition of rocks and new equipments like
trashes, storage trays and fuel containers. Vegetation on the storage
island is now finished: palm trees, bushes and twigs. Mine breach
adjusted:
move underwater mine objects.