Fix krb5_get_profile to create a new profile duplicating the list of

Fix krb5_get_profile to create a new profile duplicating the list of
files from the one in the provided context, instead of constructing
and checking the file list from scratch.  Uses a new function in the
profile library, not put into the public API yet.

* util/profile/prof_init.c (profile_copy): New function.
* util/profile/prof_int.h (profile_copy): Declare it.
* lib/krb5/os/Makefile.in (LOCALINCLUDES): Look in the profile source dir.
* lib/krb5/os/init_os_ctx.c (krb5_get_profile): Replace all the previous code
with a call to profile_copy.

ticket: 3925

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@18209 dc483132-0cff-0310-8789-dd5450dbe970