In the fFilesystem Class Documentation it refers to several functions that don't seem to exist anymore.
fFilesystem::startTransaction();
fFilesystem::rollbackTransaction();
fFilesystem::commitTransaction();
These no longer exist in the current version of fFilesystem, they appear to have been replaced by the following, respectively.
fFilesystem::begin();
fFilesystem::rollback();
fFilesystem::commit();
I think it would be prudent to update the Class Documentation to reflect this change.