* Google changed from an Inc to an LLC.
This happened back in 2017 but we didn’t notice. Officially we should update files from Inc to LLC when they are changed as part of regular edits, but this is a nightmare to remember for the next decade.
* Remove project description/titles from licenses
This is no longer part of Google’s header requirements. Our existing descriptions were useless (“Visual Blocks Editor”) or grossly obselete (“Visual Blocks Language”).
* License no longer requires URL.
* Fix license regexps.
Back-ports from Blockly Games:
* db is old and busted, ndb is the new hotness (there’s no known
difference, just pointless API churn).
* Use SHA1 which is consistent, rather than Python’s hash() which has
started changing between executions. This stops duplicate programs
from being stored.
* Restructure so that storage.py can be used as a library, with
xmlToKey and keyToXml being callable by external programs.
* Use print function compatible with Python 3.
