Update grep and awk to fit with current .h files

This commit does not change cocoa.vim behavior, but
change the way to generate indexes.

Apple changed the style in header files and
without this fix we cannot generate indexes properly from
the latest OS X and iOS Frameworks' header files.
(current OS versions are: OS X 10.9 and iOS8.1)
Update iOS version from 3.0 to 8.1

which is used for generating indexes
Update indexes and syntax