Correct a figure() bug related with the tk driver:
Correct a figure() bug related with the tk driver:

The tk driver should work in the following circunstances:
1-plain tk driver (tk_octave is not detected) -- no widgets can be built on the plserver using tk_octave.
2-tk driver with tk_octave (tk_octave is detected) -- can create/interact with tk widgets on plserver using tk_octave.
3-tk driver and tk_octave and a tcl GUI script ( tk_octave is detected, a tcl script and a plot frame are specified)
    -- the tcl script is executed, plots are made on the plot frame and 2) above is also possible.

Hope that this is final!

svn path=/trunk/; revision=3302

FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot