[TIMOB-13243] iOS: center wrapperview when required

Dupe of PR 4063 which I have closed so I can not accept. 

Fixes [TIMOB-13243](https://jira.appcelerator.org/browse/TIMOB-13243)

Regression Path
http://jira.appcelerator.org/browse/TIMOB-10330
http://jira.appcelerator.org/browse/TIMOB-7958
http://jira.appcelerator.org/browse/TIMOB-11610
http://jira.appcelerator.org/browse/TIMOB-11019
http://jira.appcelerator.org/browse/TIMOB-11707
http://jira.appcelerator.org/browse/TIMOB-11476
http://jira.appcelerator.org/browse/TIMOB-11477
http://jira.appcelerator.org/browse/TIMOB-11479
http://jira.appcelerator.org/browse/TIMOB-11377
KS->Base UI->Views->ScrollView