[mr2583] copy improved WorldLocation structure from testing branch (not use full functionality now!).
[mr2584] unification for Location/Position/WorldLocation classes chain. requires SD2 changes.
[mr2585] split usage const/non-const mapid value from WorldLocation (not must be related to any thing)
[mr2588] fix problem with link initialization on old compilers (error: ‘G3D::Vector3::x’ cannot appear in a constant-expression). thx to Termaltake.