Control the threshold for `Large Fat Error` - currently, unfortunately, hardcoded

[thoth291]

Hi,

At the line https://github.com/waveform-computing/compoundfiles/blob/dd68dec26ba04315ee6df4170946b6a6daefa54f/compoundfiles/reader.py#L439 the size of the MasterFat is said to be suspicious if it's higher than 100M.

In my case, since the file is bigger than 100GB - the total size is something like 27731*4096 ~ 108MB - so I was wondering if there is any way to turn this constrain into variable which can be overwritten in the user's application.

I had to monkey-patch the code to make it work, which is error prone and not sustainable at all.

Thanks in Advance!