Remove deprecated code

[davidism]

Remove old code that has deprecation warnings:

• Flask.ext
• Flask.init_jinja_globals
• Flask.error_handlers
• Flask.request_globals_class
• Flask.static_path
• send_file mimetype guessing removed in 0.12 Remove deprecation warnings for add_etags & mimetype guessing for send_file() #1849
• Request.module
• scripts/flask-07-upgrade.py

[davidism]

The only one I'm slightly worried about is flask.ext, but it's been deprecated almost a year now and there's plenty of information out there about what to change. We had a push to correct the use in a lot of extensions and docs, and I haven't seen it pop up for a long time on Stack Overflow. I'd rather not have it in 1.0.