Some VTOL specific

[nick87720z]

As i noticed, different unit types, depending on weapon or propulsion type, have some specific options. E.g., commanders - fire support and VTOLs - circle patrolling.

However, circle patrol may be useful for any combat unit, what seems very good on relatively large free area to secure specified area. One addition, which would be good for circle patrol, is the ability to specify radius, probably most trivial — by drawing a circle (first click specifies center, and second - radius).

And some good options for VTOL:
- height — may be specified either by fixed levels (as with attack radius, having 3 levels) or in percents of some max (e.g. highest height, where unit is still visible). Vertical maneuring e.g. may improve survivality under fire of AA missiles.
- maneuring mode. Currently even for 45 degrees vtol instantly turns in specified direction, than trying to negotiate inertia to fix course, thus loosing speed for some moment. Another corner case is to just bank without slowdown so, that it slowly turns like a plane. And of course, there could be one or more balancing modes, mixing these two in various proportions.

Also on sharp course change it could do it faster than body may turn (actual for heavy bodies). It may be possible even lock on target do some more complex maneurs around it than simple straight approach with following turn for next aproach. Btw, this would be useful for artillery howevers to move without loosing target (though probably, some lack of precision could be intended). (imho, hovers nature make them partially vtol kind).