[EventsQueryOption] Add a function to set the sort type

Currently following 2 types are defined:

* SORT_UNIFIED_ID
* SORT_TIME
[FaceRest] Add an unifiedId of latest event to event.json

Now I'm going to modify sort & pagination mechanism of events to
enable to sort by timestamp. The last unifiedId is needed to keep
consitency of pagination.
[EventsQueryOption] Fix brace position
[DataQueryOption] Add constructor of SortOrder
[DataQueryOption::SortOrder] Use const reference for arguments of constructor
[FaceRest] Shorten a verbose function name

getLastUnifiedIdOfEvent ->
getLastUnifiedEventId
[client][EventsView] Use jQuery.param() to build query part of URI
[client][EventsView] Unify building URL string
[DataQueryOption] Add functions to set/get offset
[EventsQueryOption] Enable to set lastUnifiedId

It will be used to exclude newly added events while paginating.
"startId" of DataQueryOption will be removed.
[DBClientHatohol] Use lastUnifiedId & offset instead of startId to paginate events
[testDBClientHatohol] Move lastUnifiedId from AssertGetHostResourceArg to AssertEventsArg

Because only EventInfo has it.
[client][test] Fix symbolic link of expect.js

The file "expect.js" seems be removed in recent update.
[testDBClientHatohol] Test paginating events with lastUnifiedId
[testDBClientHatohol] Replace obsolete "startId" with "offset" in a test name
[server][test] Add more test data of EventInfo
[DataQueryOption] Don't add ORDER BY statement when the direction is SORT_DONT_CARE
[testDBClientHatohol] Add tests for sorting events by time
[DBClientHatohol] Don't accept "offset" value without "limit" value
[testDBClientHatohol] Remove a needless line