Tornado's StaticFileHandler now supports content streaming, use that instead of our own implementation

Also allow for definition of access validation and serving as attachment though.

Hopefully also fixes #606, since that was possibly called by our own implementation of content streaming, which now has been removed completely.
Enable logging of tornado errors by default, to make sure octoprint.log will contain meaningful entries if something goes wrong in our tornado customization
Generate the salt used for hashing user passwords individually for each server instance
Merge branch 'master' into devel

Conflicts:
	src/octoprint/server/api/__init__.py
Preparing release of 1.1.1
Cura Plugin: Filament diameter and hotend temperature where not correctly extracted from profile and supplied to CuraEngine, resulting in low print quality

(using the default of 2.85mm filament diameter doesn't work well for 1.75mm machines...)
More work on slicing integration:

- be able to handle slicers which can't report progress
- distinguish between registered and configured slicers (e.g. to allow uploading of profiles via the settings before having saved the path to the executable)
Fix of file type detection
Fix: Don't try to create a SessionUser for anonymous users
Correctly interpret Smoothieware temperature data for multiple extruders

Fixes #633
Fix missing branch field in DEFAULT dict

Should fix an error raised on line 951 (SHORT_VERSION_PY % DEFAULT) during Octoprint setup when there's no version info. More info here: https://groups.google.com/forum/#!topic/deltabot/8udyUsJ1c9M
Also interpret lines starting with "!!" as errors from the firmware

(see http://reprap.org/wiki/G-code#Replies_from_the_RepRap_machine_to_the_host_computer)
Fixed a couple of more missing branch fields and added Changelog entry
Merge branch 'Wallacoloo-master'
Added removal of pyc files (and their parent folders if they are empty after that) to the python setup.py clean command
Merge branch 'master' into devel

Conflicts:
	CHANGELOG.md
Disable autocapitalization for username

Makes it easier to login on iPhone (Mobile Safari)
Merge pull request #639 from mangtronix/iphone-autocaps

Disable automatic capitalization for username entry field (Safari)
Merge branch 'devel' of https://github.com/foosel/OctoPrint into mrbeam