mark32 and mark64 executables help summary

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I’ve added a brief help output for the mark32.exe and mark64.exe stand alone executables. Users with heavy computing jobs often want to run them stand alone. This is particularly true for MCMC jobs that will not be pulled back into a database in either the Windows interface or RMark. The help output consists of the list of files and various parameters. You can see the help output by including the “help” parameter on the command line, or just running the executable with no input file specified.