Use new-style rights for mmap operations

Include mapping layer in capsicum.h for old-style systems; auto-detect
based on presence of CAP_MMAP_R macro.
Auto-detect old vs. new-style CAP_SEEK behaviour

CAP_PREAD is defined in new-style systems (to be CAP_READ|CAP_SEEK)
In kernel module test target, dump last part of kernel log
Tidy up after inotify test