added new instrument Complex Polygon

Feature:
polygon can be polimorphical and draw itsel using line, curveline3p and
curveline4p at once

to activate different drawing behaviour in any place of polygon it is
required to specify marked point using buttons F2, F3, F4

F2 - line
F3 - curveline3p
F4 - curveline4p

using this buttons it is possible to add new marked point or change
marker type of any existent  point of polygon
interfaces refactoring
added PhysicObject
minor changes
added generic cast to Point type
update Export serialization
added Level bean
fix problem with vec save