Simple CLI interface for serving.run_simple

Fix mitsuhiko/flask#283
Merge pull request #225 from untitaker/easy_serving

Simple CLI interface for serving.run_simple
exit -> sys.exit / python 2 style
local: add swapped operands support for LocalProxy
fix strings tests
posargs for tox
Part of a further parse_parts refactoring for generating every parser step.
naively encode fs cache keys if they arent byte strings
some naive string type fixes in werkzeug/test
some naive changes to uri/iri handling
kill a spurrious xrange from tests
switch datastructures to direct imports from six
fix a ordered multidict testcase
use detailed assertions in the datastructures testcase
Fixed import in testsuite.serving
Fixed contrib.cache
Merge pull request #1 from untitaker/python3
Fixed remaining SyntaxErrors

I know that werkzeug.script is deprecated anyway, but it still makes the
testsuite fail.
Finish cutting parse_parts out of parse_lines.
Missing assignments.