Updated INSTALL to point at packaging/ios/README
Updated README to 'facts'
Deleted ios_build_instructions as they are covered in README
[Dirk Hohndel: refactored Jan's original commit in #1241]
Signed-off-by: Jan Iversen <jani@apache.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>