support functions:
cap_subset_np() - Is cap1 a subset of cap2
cap_equal_np() - Is cap1 equal to cap2
o Introduce implementations of POSIX.1e capability support functions:
cap_copy_ext() - Externalize capability
cap_copy_int() - Internalize capability
cap_size() - Determine size required for cap_copy_ext()
Submitted by: tmm
Obtained from: TrustedBSD Project
