Additional to #30 make tweets/page accessible through menu and add a pager

The idea is to have a 'Pager' menu item atop of the timeline view.
I try to eyplain in an example for the timeline-user.

Refresh | Mark | Pager
                 Tweets per page »
                                   Default //this is the pref setting for this view
                                   10
                                   20
                                   …
                                   200 // max allowed items for statuses/user per twitter api
                 Show page »
                                   1
                                   …
                                   ((tweets_available <= max_pageable_tweets)/tweets_per_page)

Where the values for Show page will be calculated with the amount of
available tweets and the tweets/page setting.

So i thought to accomplish that i would implement a pager-menu Template
which will be filled dynamically based oh the actual settings.