Jack - fix tiff unpacking issue for IMAT

[JackEAllen]

IMAT dropped by on the 3rd May to let me know that the tiff unpacking script was not working as expected compared to IimageJ. The output values produced by the utility script were slightly off.

I suspect there is an incorrect type conversion causing this bug.

Additionally, IMAT asked for some added clarification about whether the script creates a new director if the directory does not exist.

• Resolve incorrect values from being written during unpacking
• Add additional documentation to script file to describe usage
• Add an additional method to log the date and time and whether or not the script was successful at writing all files along and the output file location files have been written too.

[JackEAllen]

IMAT have mentioned that they noticed with a dataset that they experienced negative values. This issue is not pending on receiving the dataset IMAT experienced negative values with to try and replicate. therefore placing this issue in Impeded for the time being.