There are two ways this package differs from other Go package in pkgsrc.

1. Dependencies are pre-fetched and pre-packed as DISTFILES. They are not
   actually required or used in any way at run time, and when installed
   via `go install`, they fail to build on some platforms for various
   reasons, which is not the case when simply fetched and made available
   for the Consul build to succeed.

2. The lang/go-package.mk framework is not used, because the Consul build
   only results in a single fat binary, and doesn't need the hundreds of
   source files. Also this helps avoid #1 above.

To prepare dependencies, disable the DISTFILES (re)definition and use
the 'getdeps' post-extract pkgsrc target.
