WIP.

Units works.
Need to rewrite device logic loop (put it in class).

TODO:
- add turrets and supplybay
Still WIP, but it works now.
Bugs:
- sometimes after unit destroy, ghost is left.
Working version. Cash goes v/2.
Tower damage is 5.
Added various indicators for devs and units.
Rebalance for cash usage.
Improved chat system by adding cursor.
Some code cleanup.
Fixed network check for no power.
Minor GUI cleanups.
R has now less health.
SHOT range decreased.
Moved Units logic to client side. It will reduce
server CPU load.
Removed T F S upgrades.
Fixed targeting of own devices by tanks and towers.
Fixed T syncing.
Cleanup.
NVER is now string.
Removed units.
Player need to deploy unmovable Base to start.
Some rebalance.
Base is movable again.
Gs are not auto-targeted.
Some tweaks in router logic (mainly healing).
Generator now heal Routers.
Removed PING feature (currently not needed).
Signal device have more health.
Changed class.lua members access. They are now
visible from class definition. Drawback, deleting
any class variable from object will not work now.
Yet again classes rewrite. Now super() is faster.
Now not initialized devices (not linked to net initialy)
cannot make connections.
Cleanup in devices definition.
Base now can be bought.
Revert "Base now can be bought."

This reverts commit 2bdb70061ecba6829deb452f6d4352c2d78362b5.