Logvalley b9

Changes:

• Made it so the sentry tank has one sentry at each side when spanwing, instead of only one on the top (This doesn't change the relay that is used to trigger the tank)
• Added my own (unbalanced) mission to the one of @Sergeant CrWhips, just in case somebody what's to look at how I call the sentry tank.

Fixes:

• Hopefully fixed the bug, that the sentrygun of the tank just flies in the air. (@Fillmore I couldn't recreate the bug you send me. If this bug occures again for you (or anybody else) please give me a detailed explanation on what you are doing (Mods, commands, custom pop-files, version of the map you are running, consol outputs, etc...))

Changes:

• Changed the popfile to a custom mission (mvm_logvalley_b8_normal) from @Sergeant CrWhips
  
• added slope to the building at the front
• changed second entrance and moved it to the side
• blocked the upgrade station at the front during waves

Fixes:

• fixed rocks not having collision
  
• fixed slope being misaligned with grid
• removed props to stop robots from getting stuck