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
Merge pull request #1 from yurkech/feature/ST-3_Complex_Polygon

added new instrument Complex Polygon