Massively restructured initialization to handle custom color maps. Switched to XCreateWindow instead of XCreateSimpleWindow for more power. Initialization of custom color map fairly complex in order to lead to a minimum of flickering -- low color map colors (used by window manager), cmap0 colors, and preallocated colors (used by Tk) are preserved and restored at the same pixel values to avoid undue flickering when switching color maps.  Function PLX_save_colormap added to support the latter.  All colormap state changes now done with XStoreColors which should be much speedier than the old method of freeing and allocating new cells.
Massively restructured initialization to handle custom color maps.
Switched to XCreateWindow instead of XCreateSimpleWindow for more power.
Initialization of custom color map fairly complex in order to lead to
a minimum of flickering -- low color map colors (used by window manager),
cmap0 colors, and preallocated colors (used by Tk) are preserved and
restored at the same pixel values to avoid undue flickering when switching
color maps.  Function PLX_save_colormap added to support the latter.  All
colormap state changes now done with XStoreColors which should be much
speedier than the old method of freeing and allocating new cells.

svn path=/trunk/; revision=835

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