Don't create temporary directory in same folder as file

We can't guarantee that we can delete it with secure delete. Technically we can't guarantee that we can even create this folder. Let ruby/operating system take care of the location of this folder
Merge pull request #117 from btrepp/master

Don't create temporary directory in same folder as file
Merge branch 'master' of github.com:weshatheleopard/rubyXL into comment_support