Make sure we check all the functions' return values. Minor API changes to simplify this. Checked using a patched clang that adds attribute(warn_unused_result) to all functions. This commit fixes several error handling mistakes.
Marked functions parameters that are allowed to be NULL. Some APIs were also changed. The non-obvious APIs where NULL parameter was changed to "" are master_service_init() and auth_master_user_list_init(). These checks can currently be enabled only on a patched clang: http://llvm.org/bugs/show_bug.cgi?id=6786
auth: Don't log warnings/errors when guessing a password's scheme.
Renamed strocpy() to i_strocpy(). --HG-- branch : HEAD
Added OTP and S/KEY authentication mechanisms. Patch by Andrey Panin. --HG-- branch : HEAD