[TIMOB-17663][TIMOB-17684] iOS8 fixes

Fixes [TIMOB-17684](https://jira.appcelerator.org/browse/TIMOB-17684)

Additional changes for [TIMOB-17663](https://jira.appcelerator.org/browse/TIMOB-17663)

Remove UILaunchImages from tiapp.xml template and autogenerate plist entries in CLI