* ./src/misc/modules.c: if a plugin requested not to be unloaded, then we

  * ./src/misc/modules.c: if a plugin requested not to be unloaded, then we
    won't unload it. This makes us more fault-tolerant with crap libraries
    that are making use of atexit().
  * ./configure.in: svgalib can now be a plugin.
  * ./modules/misc/gtk_main.c: gtk_main doesn't need g_atexit anymore.