* BGCorrect and Stuttermark will now exit with an error message if
  more than one input file for the same sample is specified and no
  separate output files are given. Previously these tools would
  just overwrite the output file repeatedly, discarding the output
  of all but the last data file of the sample.
* Removed to main() functions and related stubs from the tools
  because they are not actually runnable directly anyway.
* Added some more help text to some of the tools.
* Doubled the size of the marker name filter input element on the
  HTML visualisations.