The input should be a whitespace delimited file with IP addresses (in full
dotted quad or uint32 format) in the first column, and integer value in
the second column (note: value columne is not bound to 32 bits.)

Example:

128.2.1.0   10
128.2.2.0   3000

etc.

Best results will be generated with /24 addresses (but remember, the
/24s should still be presented as full dotted quads).  At smaller
numbers of bits, the labels become difficult to read.  Also, if you
plot data that has a resolution of /24 at input at an output resolution
of /16, you will get the *last* value for each /16 as the plotted
value.  The code will not automatically sum up values in the same address
block.
