Use with-open to close the new FileInputStream in the digest method taking a File as an argument.

I don't know how to write a test for the file descriptor leak -- without looking at a /proc filesystem,
or parsing the output of lsof.

I've tested this at the REPL and it works (and fixes a nasty file descriptor leak in my own program).
Merge pull request #1 from craig-ludington/fix-file-descriptor-leak

Fix file descriptor leak in the digest method with a File argument.
version 1.4.1
Added tag 1.4.1 for changeset c9dc449f535c
things are in target now
Clojure 1.4
Added tag 1.4.2 for changeset 05f938662bd5
Not required, using hook