Accept command-line input for neverallow-check.

Also, divide each sepolicy-analyze function into its own component for simplified
command-line parsing and potentially eventual modularization.
Bug: 18005561

Cherry-pick from: https://android-review.googlesource.com/#/c/111626/

Change-Id: I751a99feffe820308ec58514fdba4cdef184d964
16 files changed