licenses: convert license tags to SPDX

tools: haskell-translator: remove BracedString accidental leftover debug argument

tools: haskell-translator: comment braces.py heavily

tools: haskell-translator: python3 compat by running python-modernize

tools: haskell-translator: braces: don't copy argument to startswidth/endswith

It's never used with non-string objects, and just looks weird. I was also
curious if it impacted performance. Turns out the answer is a significant
but small yes: about 30ms, or 4.2%

tools: haskell-translator: reformat with autopep8

tools: haskell-translator: use 'is None' and 'is not None'

tools: haskell-translator: replace tabs inside strings and comments with spaces

tools: haskell-translator: autoformat python files with yapf

Import release snapshot.