Changes:
- Do not start COMMENT with "The".
- Define LICENSE and LICENSE_FILE.
- Put USE_PERL5 in the USES section.
- Install pkgconfig files into mingw32/libdata/pkgconfig instead of mingw32/lib/pkgconfig/ as suggested by portlint.
Actually, I am not sure about the pkgconfig-related change. Shouldn't those files be installed into libdata/pkgconfig?