Factor out tuple production.
MultiPartParser.cls receives parsed forms/files lazily.
yield_file/yield_form now overkill.
Fix doc
Part of a further parse_parts refactoring for generating every parser step.
Finish cutting parse_parts out of parse_lines.
Missing assignments.
Remove 'headers' from parse_lines grammar.
Test that we can stream from parse_lines.
Merge remote-tracking branch 'S11001001/parse-refactor'
Merge branch 'master' of github.com:mitsuhiko/werkzeug