Bug Fix (upload content length) and Enhancement (File Splitting)

- Bug Fix: headers for setting content length in upload were not actually being used
- Enhancement: Introduces API for splitting a file into blocks; provides one implementation of the API to split a file into uniformly sized blocks

DEPENDS: PR #24 
Starts Resolving Issue #22 
This is primarily just to ensure the function gets covered for testing; with the issues I've seen in testing the logging on EOM (where it often fails in the tests) I'm not sure I want to try testing the resulting output format to make sure it matches anything in particular.