Remove gitmodules

Integrate api and lang into core
Merge pull request #543 from thatsIch/e-remove-submodules

Remove gitmodules
Added MIT license to all api files
Merged api and lang READMEs
Merge pull request #587 from yueh/readme

Closes #584 Merged api and lang READMEs
Merge pull request #588 from yueh/api-license

Added MIT license to all api files
Update readme to reflect the api and lang repo merges

Removed recursive statement when cloning
Updated the order for building 
Clarified instruction for setup
Added information to squash commits when contributing
Format the dependencies
Added language code reference for quick look-up
Bump channel to beta