feat: Get all Rostamian's old pages working

This commit is just the last piece in the puzzle, implementing the
   perpendicular method for lines.
   Resolves #36.

src/adapptlet.civet

@@ -257,6 +257,7 @@ function jToG(
       cmdr.callbacks.push (api: AppletObject) =>
          for each aux of cmdr.auxiliaries
             api.setAuxiliary aux, true
+            api.setLabelVisible aux, false
             api.setVisible aux,false
 
    // set up the pivot if there is one
@@ -405,7 +406,6 @@ function pivotListener(slider: string)
    for each anchor of pd.rotatable
       relX[anchor] = pd.api.getXcoord(anchor) - pX
       relY[anchor] = pd.api.getYcoord(anchor) - pY
-      console.log 'Unfixing', anchor, relX[anchor], relY[anchor]
       pd.api.setFixed anchor, false
    ct := Math.cos rotation
    st := Math.sin rotation
@@ -414,7 +414,6 @@ function pivotListener(slider: string)
       rY := relY[anchor]*ct + relX[anchor]*st
       pd.api.setCoords(anchor, rX + pX, rY + pY)
       if pd.fixed[anchor]
-         console.log 'Re-fixing', anchor, rX, rY
          pd.api.setFixed anchor, true
 
 function invisible(cname: string): boolean
@@ -712,6 +711,41 @@ classHandler: Record<JoyceClass, ClassHandler> :=
                madeSegment = true
             else
                commands.push `${aux}2 = Translate(${oldEnd}, ${aux}1)`
+         'perpendicular'
+            pt := args.subpoints
+            unless pt then return
+            inPlane .= ''
+            if cdata.is3d
+               unless args.plane?.length is 1 then return
+               inPlane = `,${args.plane[0]}`
+            switch pt.length
+               when 2
+                  ends[0] = pt[0]
+                  ends[1] = aux
+                  auxiliaries.push aux
+                  if args.line?.length is 1
+                     ln := args.line[0]
+                     commands.push
+                        `${name} = Rotate(${ln}, 3*pi/2, ${pt[0]}${inPlane})`
+                        `${aux} = Vertex(${name}, 2)`
+                     madeSegment = true
+                  else
+                     commands.push
+                        `${aux} = Rotate(${pt[1]}, 3*pi/2, ${pt[0]}${inPlane})`
+               when 3
+                  return // TODO: line perpendicular to plane
+               when 4
+                  ends[0] = pt[0]
+                  ends[1] = aux + 2
+                  auxiliaries.push aux+1, aux+2
+                  commands.push
+                     `${aux}1 = Rotate(${pt[1]}, 3*pi/2, ${pt[0]}${inPlane})`
+                  unitVec := `UnitVector(Vector(${pt[0]}, ${aux}1))`
+                  dist := `Distance(${pt[2]}, ${pt[3]})`
+                  commands.push
+                     `${aux}2 = Translate(${pt[0]}, ${dist}*${unitVec})`
+               else return
+
       unless madeSegment
          commands.push `${name} = Segment(${ends[0]},${ends[1]})`
       callbacks.push (api: AppletObject) => api.setLabelVisible name, true