User not asked to revalidate Moodle repeatedly.

Following changes were made in this:
1. The user is now not asked to revalidate the Moodle account from the
Evernote account repeatedly.
2. Solved the bug when the user declines the permission to Moodle from
Evernote account.
3. Removed the bug which gave the error: 'Warning:
file_get_contents(write.txt): failed to open stream: No such file or
directory in
/home/fred/www/repositories/sm/moodle/portfolio/evernote/lib.php on line
184'
4. The note title is shown in big fonts on the export summary page.
5. Replaced dirname(__FILE__) with __DIR__
6. Tabs  as white spaces removed from the code.
7. list_notebook function is now protected instead of private and now
returns a list of notebooks rather than setting the class variable.
8. Removed the strings from the language file which are not needed for
translation.