Adding compact page selection options. Thanks to Felix Egli for idea, patch

Adding compact page selection options. Thanks to Felix Egli for idea, patch
and other fixes.
Fixed incorrect declaration of $data_dir variable
Removed getPref calls for page selector, because they are already loaded
in load_prefs

git-svn-id: https://svn.code.sf.net/p/squirrelmail/code/trunk/squirrelmail@8312 7612ce4b-ef26-0410-bec9-ea0150e637f0