updated backend for data dir and better sync

1) updated backend to sync input files
2) updated backend to delete experiments and input files if they
are not on the server. Otherwise, we will never be able to stop
experiments
adding utils for determining what to sync
fixed syntax bugs and unecessary addition of .py
we now sync data and check the md5 of files
updated utils to use base64 encoding
fixed syntax errors from merge
updated centinel backend to do syncs without exts
updated utils and backend to be ext independent
Merge pull request #84 from ben-jones/add_input_files

Add input files