Bring it out of sysdb, which will slowly remove internal dependencies on
domains and instead will always require them to be passed by callers.

This is useful for wiping passwords, as it prevents the compiler from
optimizing out a memset to zero before a free()

Added new parameter to split_on_separator that allows to skip
empty values.

The whole function was rewritten. Unit test case was added to
check the new implementation.

https://fedorahosted.org/sssd/ticket/1484

In some case we allocate and assign data to a const pointer.
When we then try to free it we would get a const warning because talloc_free
accepts a void, not a const void pointer. Use discard_const to avoid the
warning, it is safe in this case.

This reverts commit ff57c6aeb80a52b1f52bd1dac9308a69dc7a4774.

This commit doesn't really make sense, we are never accessing freed
memory as all we are dealing with is a pointer which is never itsef
part of the memory we are freeing (if it were, it would be an error
in the caller and we shouldn't mask it in this macro).

If global variable debug_level has value SSSDBG_UNRESOLVED, we should
print at least fatal and critical errors.

https://fedorahosted.org/sssd/ticket/1345

Since the PAC responder is used during the authentication of users from
trusted realms it is started automatically if the IPA ID provider is
configured for a domain to simplify the configuration.

Fixes https://fedorahosted.org/sssd/ticket/1613

string_in_list() and add_string_to_list() are two utilities for NULL
terminated strings arrays. add_string_to_list() adds a new string to an
existing list or creates a new one with the strings as only item if
there is not list. string_in_list() checks if a given string is in the
list. It can be used case sensitive or in-sensitive.

Return EINVAL if number of tries is <= 0. Also the parameter
retries was renamed to num_tries, so it is more obvious that
it also includes the first try.