[openadk] option to give output folder

Hi, I’d like to discuss an idea that has been raised by some members of my team: Working on the mac requires us to work on an explicitly mounted case-sensitive file system. Normally our devs prefer to work from within a specific file-location, e.g. ~/workspace or similar arrangements, that is not case-insensitive. This doesn’t work for OpendADK obviously. So we took a look into introducing an ADK_OUTPUT_DIR environment variable. When this is given, it puts most of the generated files into the output dir (under the otherwise same names). The thing mostly missing is the various Config.* files generated, as kconfig seems to insist that these are relative to each other and can’t deal with some sort of include-paths. As a side-effect, this work uncovered a few places that got mildly cleaned up (such as prereq.mk and some hard-coded paths like ${STAGING_TARGET_DIR}/scripts that should read ${SCRIPT_TARGET_DIR} etc. Of course when not using this, there should be no effect, and as far as I can see, there is none. My question is: as this is a bigger change, maybe even philosophical in nature, I’d like to get opinions of the community first, before investing more. Because if nobody wants it, and it’s not taken into consideration while working on OpenADK, it might quickly fall into disrepair, and then it’s better to not do it at all :) I tried to push the changes (two commits) for review on a branch to gogs.waldemar-brodkorb.de <http://gogs.waldemar-brodkorb.de/>, but that got stuck and didn’t progress even after a long wait - so maybe there is something awry there. Cheers, Diez