rename memset_s to memset_secure
print errno and strerror(errno) in syscall error messages
adjust more error messages
reenable outputs on mkstemp_ex and rename_ex
fix spelling
Merge pull request #407 from cgzones/memset_secure

rename memset_s to memset_secure
Merge pull request #401 from cgzones/syscall_errors

syscall errors
add -Werror flag
fix unused variable warning
do not use special warnings for tests
cast const away for in-macro assignment