Possibly write the truncate function so that vim will work

[MarkCMann]

Currently, vim pulls all file data into a buffer and then truncates the file to 0 and rewrites all data within the file. Thus, to benefit our presentation on Tuesday I think we should write truncate.

[MarkCMann]

This will be harder than I thought because the truncate function does not take the fuse_file_info struct. Thus we cannot differentiate files of the same name but on more than one server unless the user differentiates them for us.

We might want to throw an error if the user decides to be this malicious.