Update incognito mode ewk API

Update incognito mode ewk API

[Issue] https://bugs.tizen.org/jira/browse/TT-230
[Problem] Using deprecated function
[Solution] Added new function and reorganization of
of current incognito mode solution
[Verification]
1. Open page in incognito mode
2. Type URL that do not exist it the history
3. Type enter

New URL shouldn't be inserted into history.

4. Close browser with ctrl+c
5. Open browser again

Browser should open without the tab last opened
in incognito mode.

Change-Id: Ia4548e628b30d57e58f9aeee3c4563e39705ab27