Portlint tries to verify the content of a package directory.
The purpose of portlint can be separated into two parts:
 (1) to let the submitters easily polish her/his own package
     directory, and
 (2) to decrease the labor of the committers.

Portlint uses very simple regular-expression matching for verifying
files that make up a package directory.  Note that it does NOT implement
complete parser for those files.  Because of this the user may see some
extra warnings, especially when checking complex Makefiles.