Add more vars to actions

New:

• Lifted restriction of 2 vars per state (maximum is now 8)
• Lifted restriction of 2 arguments per action
• Lua: Added vars[] to states
  • This is 1-indexed, so vars[1] is the first var, vars[2] is the second var, etc.
  • Accepts a table when setting (maximum accepted amount of vars is 8)
• SOC: Added VAR3 to VAR8
• Added dynamic typing to vars. Types:
  • integer
  • boolean (true, false)
  • string
  • null

Backwards compatible:

• state.var1 is equivalent to state.vars[1]
• state.var2 is equivalent to state.vars[2]

Backwards incompatible:

• Calling actions scripted with Lua without the sufficient number of arguments will push nil instead of the number zero.

Example for testing: action_test.wad