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  CLASS: Bitmap     --JKH
  PUBLIC METHODS:
    Bitmap() :        constructor; default length = 0
   Bitmap(UINT32):  constructor; use length = specified # of bits      
    numBytes() :      return # of bytes allocated to bitmap
    numBits() :       return # of bits in bitmap
   setBit(UINT32):  set the specified bit
   clearBit(UINT32):clear the specified bit
   readBit(UINT32): returns the value of the specified bit
   resize(UINT32):  resizes the bitmap to the specified number of bits
 
  USAGE NOTES:
   For internal use only.
  
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