UrlHistoryList: adjusting height to the items number.

UrlHistoryList: adjusting height to the items number.

[Issue]    https://bugs.tizen.org/jira/browse/TT-161
[Problem] When displayed small number of items in a list, fragment of
list widget was stopping cursor focus events.
[Cause] Widget size was bigger then sum of items height for small
amount of items.
[Solution] Resizing list depending on the number of added items.
[Verify] Area under list should not block cursor focus events. E.g. in
QuickAcces 'Most visited' button should be cursor-focusable for one
item on a UrlHistoryList.

Change-Id: Ie9a0898e78cd42de8df2b97ca88321ed0361ac99
Signed-off-by: Adam Skobodzinski <a.skobodzins@partner.samsung.com>