Platform Build - Added 'sf-postbuild' onto deps for 'sf-build-noprep' as although it isn't the best place to have it, it's the same as the deps for the version in 'common' and is needed for the external Hudson jobs.

Ensured build environment is always compared with expected environment, whether or not it would abort the build because of it.

Changed building of tools targets so that it builds the targets listed in ${sf.spec.sbs.tools.config}, in sequence, rather than just buildng tools2_rel.whatlog followed by tools_rel.whatlog, regardless of the property.