[client][actions] Revert an input element with csrf_token.

Without this element, Django (CsrfViewMiddleware) doesn't always
sent a CSRF cookie (It seems to sent for the first access
from a client). However, this causes the troubles.
E.g.)
- When multiple web browsers are used in one computer, the send
  one doesn't get a CSRF cookie.
- After a CSRF cookie expires or when a CSRF cookie is deleted
  manually, a browser may not get a cookie immediately.
[DBClientHatohol] Add a privilege to see all events.
Merge branch 'issue58'
[client][view][events] Extract JS code in events view to the JS file.

The purpose is to improve independency of the JS code (in other words,
modularization).
[client][po] Update messages.
[HatoholMessageBox] Show a server error code if the status code is REPLY_STATUS.ERROR_CODE_IS_NOT_OK.
[HatoholMessageBox][test] Add a new test: 'hatoholMsgBoxForParser on a server error'.
[HatoholMessageBox][test] Close a dialog box after a test finishes.
[HatoholMessageBox][test] Verify the status too.
[client][EventsView] Reuse a HatoholConnector object while it is alive.
[client][EventsView] Create elements in JS code dynamically.
[client][EventsView] Form a function to setup event callbacks.
[client][EventsView] Add a 'To next' button to get the next events.
[client][EventsView] Scroll to the top when the next events are shown.
[client][EventsView] Strengthen the coupling to itself.
[client][EventsView] Get a sort order and the number of events in a page with UserConfig mechanism.
[client][EventsView] Extract some lines to a function to improve readability.
[client][EventsView] Show the number of events per page.
[client][EventsView] Fix a bug that doesn't get the intended value.
[client][EventsView] Store a config value: num-events-per-page.