Merge pull request #411 from fichtner/format_string_fix

fix clang errors
fix clang errors

error: format string is not a string literal (potentially insecure)
    [-Werror,-Wformat-security]

(follow up on ceb91d4bf9b01b7272c509a1c9674d217e2b2384)
fix #407 for real
Merge pull request #412 from fichtner/zbeacon_freebsd

fix #407 for real :D