Add CF_EXTERN_C_END to CFTimeZone.h.

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/corebase/trunk@36005 72102866-910b-0410-8b05-ffd578937521
Merge remote-tracking branch 'upstream/master'
CFURL: Add missing string constants that were declared in the header.