Use global "verbose level" & "tool name" iff no tracee is available.

That way, the "notice()" and "VERBOSE()" functions can comply to the
requested verbose level in finalization stages.  For instance:

Before:

    $ care -v -1 echo OK
    care info: concealed path: $HOME /usr/local/cedric
    care info: concealed path: /tmp
    care info: revealed path: $PWD /usr/local/cedric/Git/proot
    care info: revealed path: /bin/echo
    care info: ----------------------------------------------------------------------
    OK
     info: ----------------------------------------------------------------------
     info: Hints:
     info:      - if the execution didn't go as expected: search for "conceal" in `care -h`
     info:      - use the following command to extract the archive: cpio -idmuvF 'care-131213165425.cpio'

Now:

    $ care -v -1 echo OK
    OK

Also, a couple of messages were raised from "warning" to "error", so
as to be printed even if a negative verbose level were specified.
care: Add option "-x file, --extract=file" to extract CARE archives.

It is recommended to use this option to extract archives created by
CARE because most extracting tools -- that are not based on libarchive
-- are too limited to extract them correctly.
care: Add auto-extractable format, make it default.
care: Add support for DBUS & KDE applications.
Prepare release of CARE v2.1.
care: Consolidate extract_archive_from_file() a little bit.
care: Ensure '/' cannot be declared volatile.

This can happen by accident or explicitly, in both cases it is
meaningless.
care: Add support for "tar" format + rewrite the output suffix parser.
care: Add support for "copy" format.

When output file suffix is "/", content is copied into the specified
directory instead of being archived in a file.

Suggested-by: Ryan Fortman <ryanfortman@gmail.com>
care: Rewrite the "extract" feature to not rely on mmap(2) anymore.

It is not possible to memory map archives > 3GB on 32-bit systems.
care: Update documentation.
care: Add test for non-regular files + use GNU tar as .bin internal format.