Adding support to override, via static_url, whether the generated URLs
should include the version signature or not.
Introduce StaticFileHandler.(get_content|set_headers) which reduces the
complexity of the HTTP GET handler of static resources.
Fixed syntax error in the altered StaticFileHandler.get() method
Move retrieval of absolute path to separate method which is also in
charge of validation.
Cache the computed absolute path to the requested resource in
StaticFileHandler. The cache is cleared on_finish of each request
in order to ensure recomputation on each request.
Make options instance more dict-like.
Use 'get_version' to calculate static file hashes.
(incomplete) Honnoring Range request header
Fix bytes/str issues
Set Accept-Range header, return 406 on invalid range
Tests for Range header
Handle negative byte ranges
options[key] should return a value, not an _Option instance
Replace options.as_dict() with group_dict()
Return HTTP 416 Range Not Satisfiable, not 406
Fixing errant paren, missing format value
206 in response to Range, refactor ETag checking
Update redbot tests to work with current versions of redbot.
Merge remote-tracking branch 'wolever/accept-range-in-static-file-handler' into merge
Merge remote-tracking branch 'birknilson/refactoring/reduce_statichandler_complexity' into merge

Conflicts:
	tornado/web.py