add APIs, and implements
added /.../destroy apis.
refuctored.
起動時のエラー解消
フォーマットとシンタックス修正
共通化処理
*_handler.js内の同じ処理を継承するように変更
added auth API, /auth/login, /auth/logout.  But both of them are test
implementation.

To use auth API, you need several steps.
1. insert user data.
1.1. mongo (run console)
1.2. use atmosphere
1.3. db.users.insert({"username":"name of user", "password":"password
for user"})

Usage:
1. call /auth/login with post data {"user_id":"...", "password":"..."}
2. response {"session_id":"..."}
3. call /auth/logout with post data {"session_id":"..."}

Known issues:
1. session_id must be stored into header of request/response.
2. password must be encripted(hash + salt).
Pathからの共通化を修正
Merge branch 'motegi-branch' into implementsApis
warning 修正
use Object.keys(target).length instead of __count__.
fixed problem: /messages/say was called, stored to "monolog" collection.
- collectionName : changed to atmos_handler's instance property.
- each handlers : changed to references this.collectionName
- handlers : when call handler function, changed to use "call" function
  with provided target object
refactored: added RequestInfo which has functions to access http request
information.
added user_id and created datetime(UTC) when inserting some information
to database.
sort descending order by created datetime when getting timeline
information.
implements login, logout, and whoami APIs.
implements authorization checking logic.
removed APIs: messages/say, messages/talk.
added API: messages/send.
updated:
- the timeline API:
 - returns count, results, latest date of results, oldest date of
   results.
 - enabled to specify the range of "created_at" using "future_than",
   "past_than", and both.

bug fixed:
- fixed issue that parsing query string is failed.
added API /user/list that obtain existing user information.
refactored range condition when calling persister#find.
implemented /messages/response, /announce/response, and
/private/response.
This is related with github issue #3