Merge pull request #55 from pkit/tests_fixes

replaced methods with static functions in tests
changed SwiftPath to better support various URLs

now can use container only or account only URLs in `swift://` path
Merge pull request #56 from pkit/minor_fixes

changed SwiftPath to better support various URLs
fixed bad behavior when rewriting output

In case where output device has `Content-Type` : `message/cgi` or 'message/http` and it's a `WRITABLE` device and it is a local device the file needs to be rewritten on disk

Why?

Because if it's a writeble local file it will be relocated to be an object in-place and then we need to delete all the `message` headers from it. Headers are only needed when such object is sent back over HTTP, but not when it's stored.
To rewrite such object we used mkstemp() which creates a file in `/tmp` by default. But according to Swift rename rules temp object must be on the same device as the intended real object.
This patch uses mkstemp(dir=swift_temp_dir) which places the temp files in a correct dir
Merge pull request #57 from pkit/object_fixes

fixed bad behavior when rewriting output
refactor config variables in middlewares

optimized load of the config files in proxyquery and objectquery
now both of them will load some vars from corresponding server config (proxy-server or object-server)
it should avoid duplicating vars for both middleware section and server section
move retcode_map to module level constant
Merge pull request #58 from pkit/minor_fixes

refactor config variables in middlewares
now you can run zerovm on container server

added a new feature that allows you to specify Swift container database as one of the input files for the instance
proxy middleware support for container jobs

added support for querying container db files
better detection of container query

currently the only channels that can be usable for running zerovm on container db are `stdin` and `input`
fixed tests to rely one their own Ring classes

some tests were relying on specific files in `/etc/swift`
removed that
Merge pull request #60 from pkit/minor_fixes

fixed tests to rely one their own Ring classes
Merge pull request #59 from pkit/feature_container

support for running jobs over container sqlite3 database file
major bugfix patch for 404 errors

a lot of 404 was not handled correctly due to badly designed support for write-only objects
it lead to 5xx instead of 404 or 400 in quite a few places
needed to redesign the whole thing and check for 404 much earlier than before

wrote some regression tests
hope that all corner cases are covered now

Side note:
This patch uses `x-zerovm-access` header internally. And its value can be `GET` or `PUT`. Usually adepts of RestFul will ask "Why not use HTTP GET and HTTP PUT instead?" my answer would be: "Think."
Merge pull request #61 from pkit/bug_fix

major bugfix patch for 404 errors
added sysimage config to container servers

will be used in future tests
otherwise will forget it