Install azavea.libgdal-java role; add as dependency to common role
Make local IP detection mechanisms compatible with Linux
Remove `eth` var definition from all, ensure it exists in dev and prod
Expand no_proxy setting to cover Sonatype repositories

Polipo doesn't seem to play well with Sonatype repositories. In order to
ensure that requests to those repositories bypass the proxy when it is
enabled:

  ./sbt -Dhttp.nonProxyHosts="$(echo $NO_PROXY | sed 's/,/|/g')"

(`sed` snippet is replacing the delimiters from `,` to `|`.)
Merge pull request #903 from hectcastro/hmc/libgdal-java

Add GDAL Java bindings