Bug 883058 - [SMS/MMS] One contact with very long name can be scrolled in recipient field r=gnarf

https://bugzilla.mozilla.org/show_bug.cgi?id=883058

- Removes rule about a single contact prohibiting pull down
- Height of recipient-list itself is informative enough to determine "pullable" status
- http://en.wikipedia.org/wiki/Taumatawhakatangihangakoauauotamateapokaiwhenuakitanatahu

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>