Clarify an unclear comment pointed out by Steve Long.
There are cases when the long options are of the format abc-def. In current implementation FLAG_xxx macros are generated for long options too. with __-__ sign in the macro, it will generate errors.

I am of the opinion that __-__ be converted to '_' for generating the FLAG_xxx macros and be used in the command.

This will enable the user to 'abc-def', but be handled like 'abc_def' in code.
Fix mkdir -p with absolute paths.

Stripping leading / is not the right thing to do there.
Broken when the code moved to lib and was genericized for use elsewhere.
Most of the remaining cpio cleanup.
Several cpio bugfixes spotted by Isaac Dunham.
Promote cpio out of pending.

After some waffling I put it in "posix", even though it was last specified in
susv2 (where it was the obsolete 6 byte header entries predating susv4).

LSB specifies it, including the 8 byte header fields, but for the actual
command it just references SUSv2. (LSB isn't so much a standard as Red Hat's
"notes to self".)
More cpio bugfixes from Isaac Dunham.

Fix FLAG_o to actually be 1 like the comment says, don't try to strlen(name) before reading it, pad TRAILER!!! entry correctly.
Fix cpio -it: don't close(fd) unless we opened it.
Add help -a (to show all commands) and -h (to produce HTML output).
Add help.html (make defconfig && help -ah > help.html) to index.