do not enforce markers in pzmap

Author: baggepinnen

src/plotting.jl

@@ -730,15 +730,15 @@ pzmap
         z,p,k = zpkdata(system)
         if !isempty(z[1])
             @series begin
-                markershape := :c
+                markershape --> :c
                 markersize --> 15.
                 markeralpha --> 0.5
                 real(z[1]),imag(z[1])
             end
         end
         if !isempty(p[1])
             @series begin
-                markershape := :x
+                markershape --> :x
                 markersize := 15.
                 real(p[1]),imag(p[1])
             end
@@ -749,7 +749,7 @@ pzmap
             S,C = sin.(v),cos.(v)
             @series begin
                 linestyle --> :dash
-                c := :black
+                linecolor := :black
                 grid --> true
                 C,S
             end