sbo-maintainer-tools (sbolint and sbopkglint for SBo maintainers)

These are "lint" tools to make life easier for SlackBuilds.org
maintainers and admins:

sbolint: checks your SlackBuild, README, .info file, and slack-desc.
sbopkglint: checks your package, after it's built.
sbofixinfo: attempts to fix common problems with SBo .info files.
pre-commit-sbolint: git hook you should use, that automatically calls
sbolint and stops you from committing bad code.
sbodl: downloads source URLs, optionally using the SBo source archive.
