licenserecon: Check licenses listed in d/copyright file against licensecheck.

lrc  parses  a valid DEP-5 copyright file and notes the licenses of all files
in the source tree. Licensecheck is then run, and the results compared.
Differences between licenses and license versions in debian/copyright
and the output of licensecheck are reported.

It should be run in the top level of a cleaned Debian source tree,
with a valid DEP-5 copyright file. The source tree should be clean,
otherwise results may be contaminated by spurious reports on the build's
generated files. It is advisable to run lintian first to ensure correct syntax
of debian/copyright.

The results are indicative only, and not a substitute for manual checking.
It is intended to report obvious errors. The design intends to minimise false
positives as much as is practical. However, false positives will occur if the
spelling of the license short-string is not identical between the file and
debian/copyright. This is quite likely with complex licensing such as
'and'/'or' constructs and specific exceptions.

Only files with a copyright header are checked. False negatives may occur if
licensecheck cannot determine a file's license. Files named copyright, copying,
readme etc. are not checked as they often specify the licenses of other files
rather than their own.

EXIT CODES
    0: No differences found
    1: Failure to run (no debian/copyright or options invalid)
    3: License differences found

SAMPLE OUTPUT
    Sample output invoking lrc.

    SUCCESS:
        Parsing Source Tree ....
        Running licensecheck ....

        No differences found

    DIFFERENCES:
        Parsing Source Tree ....
        Running licensecheck ....

        d/copyright     | licensecheck

        LGPL-2.1+       | GPL-2+       test/src/config/chan.c
        GPL-2+          | public-domain share/lua/int/dummy.lua
        GPL-2+          | LGPL-2.1+    modules/access/sr_common.h

OPTIONS
Options are case-insensitive. Invalid options are ignored.

-? -h or --help
Writes this readme file to stdout.

-v or --version
Writes the version numbers of licenserecon and licenscheck to stdout, then exits

-s or --struct
Structured output.
Outputs the d/copyright licence, licensecheck license, and filename
on three separate lines, followed by one blank line.
Headers and summary lines are suppressed. Version info is not output
unless specified via -v option.

-l or --long
Output is generated for every file in the source tree, not just those
with license discrepancies.

-t or --terse
Where blocks of files with identical license differences would be output,
only the first file is shown. Overrides -l (if specified)
