Cvsplot 1.6.5 released

* Made a number of changes to support CVS repositories running under
Windows, and for running cvsplot against these repositories. The
format of Window CVS diffs are slightly different to cause a number
of minor changes, plus the script had a number of UNIXisms in it
which needed to be removed to make the script cross-platform.

Note the line count may change slightly from previous versions.
Prior to this version, the "wc -l" command was used to count lines
for 1.1 files, however this command counts the number of _newline_
characters found, which is slightly different to the number of lines
present in a file. The correct count is now used.

* Added the -gnuplot option so that the gnuplot binary can be
specified, which is convenient for Window platforms.