BG - fix check of topology plugin
Convert hostlist functions on a multi dimensional system to use a bitmap
instead of a large array.  This appears to speed up the process a big deal
before we were seeing times of over 6000 usecs just to memset the array
for a 5D system.  With this patch on average the whole process takes
around 1000 usecs with many being way under that.
Get rid of errors when using 64 bit bitmaps (nothing sets USE_64BIT_BITSTR
today) so bitmaps are always 32bits.  If one would like to use 64bit
bitmaps just #define USE_64BIT_BITSTR in config.h.