Updated the readme to be more descriptive.

Updated readme; deleted old files; moved some files to the wiki.

stripped the readme down to bare bones; codalab.github.io contains the big discussion now.
Updated Azure logo since it is now branded 'microsoft azure'.
Add additional means of discovering file type on file upload. Merge master.
Merge pull request #441 from cpoulain/master

Add additional means of discovering file type on file upload.
Add user ID to name lookup for use by CLI.
Merge pull request #442 from cpoulain/master

Add user ID to name lookup for use by CLI.
Merge pull request #439 from willum070/logo

Updated Azure logo since it is now branded 'microsoft azure'.
Merge pull request #428 from willum070/docs

Updated the readme to be more descriptive.
Merge branch 'master' of https://github.com/codalab/codalab into dev