Resolve CRAN checks for 1.0.17-12 submission

[gothub]

@mbjones The recent CRAN submission has produced a testing error and warnings: https://cran.r-project.org/web/checks/check_results_redland.html

These are related to the configure script. This script was changed in this release to resolve a previous warning generated by the checkbashisms check. This check inspects the configure script and generates warnings if any non-POSIX compliant statements are used.

Since this check was added at the end of 2019, I had assumed that the configure script needed to be converted to use POSIX compliant #!/bin/sh. The changes that were made to do this caused an error on Solaris.

Looking closer at checkbashisms, and how it behaves on different OS types, the change that should have been
made was to simply change the configure script to use #!/usr/bin/env bash. If this is used, checkbashisms appears to not be run. This is what the R package jeroen/v8 configure script is doing, and it has passed all the tests. Our 'configure' script was written by Jeroen (thanks!) and is very similiar to his v8 version.

So, in order to recover from this problem, I'll use the same bash invocation as v8, and run rhub tests for ALL CRAN platforms.

[gothub]

Update - the Solaris platforms for rhub do not have a librdf library that is required for the R redland package builds, see r-hub/rhub#413. Since CRAN is able to test on Solaris, they do have some way to build these, maybe they are performing these manually, as the Solaris library repository does not have librdf: OpenCSW https://www.opencsw.org/get-it/packages/.

Also, rhub builds have been updated for Fedora months ago for the new checkbashisms CRAN check, but new images have not been deployed: https://builder.r-hub.io/status/redland_1.0.17-13.tar.gz-0a87263b135749f386e1c44259ba3fe8

[gothub]

The configure script has been converted to be 100% Bourne shell compatible, which resolves syntax errors encountered on CRAN Solaris build/check and 'checkbashisms' checks on Fedora.

This was fixed in commit fa7ad7d