Added PL_OPT_DISABLED, and not that PL_OPT_ENABLED is obsolete.  Removed TK related function declarations -- prototypes for these now must be obtained by including pltk.h.
Added PL_OPT_DISABLED, and not that PL_OPT_ENABLED is obsolete.  Removed
TK related function declarations -- prototypes for these now must be
obtained by including pltk.h.

svn path=/trunk/; revision=1587

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