0022877: Implementation of DRAW commands for non-regression testing:

- TKIVtkDraw toolkit provides IVtk packages functionality in DRAW.

- it allows to create VTK interactive view in regular or virtual mode (virtual windows),
  display OCC objects and dump them.

- TKIVtkDraw provides also test commands: ivtlinit, ivtkdisplay, ivtkerase, ivtksetdispmode,
   ivtksetselmode, ivtkmoveto, ivtkselect, ivtkfit, ivtkdump, ivtkbgcolor.

Corrected offscreen rendering mode.

Moved vinit command from /v3d/begin script to avoid unused occ view in ivtk tests.

src/TKIVtkDraw/EXTERNLIB

@@ -0,0 +1,18 @@
+CSF_VTK
+CSF_TclLibs
+CSF_TclTkLibs
+TKernel
+TKBRep
+TKDraw
+TKG2d
+TKG3d
+TKGeomAlgo
+TKGeomBase
+TKMath
+TKMesh
+TKService
+TKTopAlgo
+TKV3d
+TKOpenGl
+TKIVtk
+

src/TKIVtkDraw/FILES

@@ -0,0 +1,2 @@
+PACKAGES
+EXTERNLIB

src/TKIVtkDraw/PACKAGES

@@ -0,0 +1 @@
+IVtkDraw